[v10,04/11] drm/sun4i: tcon: Compute DCLK dividers based on format, lanes

pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
MIPI clock topology in Allwinner DSI controller.

TCON dotclock driver is computing the desired DCLK divider based on
panel pixel clock along with input DCLK min, max divider values from
tcon driver and that would eventually set the pll-mipi clock rate.

The current code is passing dsi min and max divider value as 4 via
tcon driver which would ended-up triggering below vblank wait timed out
warning on "bananapi,s070wv20-ct16" panel.

 WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
 [CRTC:46:crtc-0] vblank wait timed out
 Modules linked in:
 CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
 Hardware name: Allwinner sun8i Family
 Workqueue: events deferred_probe_work_func
 [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
 [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
 [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
 [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
 [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
 [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
 [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
 [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
 [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
 [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
 [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
 [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
 [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
 [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
 [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
 [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
 [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
 [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
 [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
 [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
 [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
 [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
 [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
 [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
 [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
 [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
 [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
 [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
 [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
 [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
 [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
 [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
 [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
 [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
 [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
 [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
 [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
 [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
 Exception stack(0xde539fb0 to 0xde539ff8)
 9fa0:                                     00000000 00000000 00000000 00000000
 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 ---[ end trace 4017fea4906ab391 ]---

But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div

Which would compute the pll_freq and set a clock rate for it in
[3] and [4] respectively.

The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
and got fixed with this computation logic 'format/lanes', so this patch
using dclk min and max dividers as per BSP.

[1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
[2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
[3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
[4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161

Tested-by: Merlijn Wajer <merlijn@wizzup.org>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
  

On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> MIPI clock topology in Allwinner DSI controller.
>
> TCON dotclock driver is computing the desired DCLK divider based on
> panel pixel clock along with input DCLK min, max divider values from
> tcon driver and that would eventually set the pll-mipi clock rate.
>
> The current code is passing dsi min and max divider value as 4 via
> tcon driver which would ended-up triggering below vblank wait timed out
> warning on "bananapi,s070wv20-ct16" panel.
>
>  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
>  [CRTC:46:crtc-0] vblank wait timed out
>  Modules linked in:
>  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
>  Hardware name: Allwinner sun8i Family
>  Workqueue: events deferred_probe_work_func
>  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
>  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
>  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
>  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
>  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
>  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
>  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
>  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
>  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
>  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
>  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
>  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
>  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
>  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
>  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
>  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
>  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
>  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
>  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
>  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
>  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
>  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
>  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
>  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
>  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
>  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
>  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
>  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
>  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
>  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
>  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
>  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
>  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
>  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
>  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
>  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
>  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
>  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
>  Exception stack(0xde539fb0 to 0xde539ff8)
>  9fa0:                                     00000000 00000000 00000000 00000000
>  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
>  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
>  ---[ end trace 4017fea4906ab391 ]---
>
> But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
>
> Which would compute the pll_freq and set a clock rate for it in
> [3] and [4] respectively.
>
> The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> and got fixed with this computation logic 'format/lanes', so this patch
> using dclk min and max dividers as per BSP.
>
> [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161

In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html

The only reply you've sent is that you indeed see that the divider is
set to 4 in the BSP, but you're now saying that the BSP can change
it. If so, then please point exactly the flaw in the explanation in
that mail.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
  

On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > MIPI clock topology in Allwinner DSI controller.
> >
> > TCON dotclock driver is computing the desired DCLK divider based on
> > panel pixel clock along with input DCLK min, max divider values from
> > tcon driver and that would eventually set the pll-mipi clock rate.
> >
> > The current code is passing dsi min and max divider value as 4 via
> > tcon driver which would ended-up triggering below vblank wait timed out
> > warning on "bananapi,s070wv20-ct16" panel.
> >
> >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> >  [CRTC:46:crtc-0] vblank wait timed out
> >  Modules linked in:
> >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> >  Hardware name: Allwinner sun8i Family
> >  Workqueue: events deferred_probe_work_func
> >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> >  Exception stack(0xde539fb0 to 0xde539ff8)
> >  9fa0:                                     00000000 00000000 00000000 00000000
> >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> >  ---[ end trace 4017fea4906ab391 ]---
> >
> > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> >
> > Which would compute the pll_freq and set a clock rate for it in
> > [3] and [4] respectively.
> >
> > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > and got fixed with this computation logic 'format/lanes', so this patch
> > using dclk min and max dividers as per BSP.
> >
> > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
>
> In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
>
> The only reply you've sent is that you indeed see that the divider is
> set to 4 in the BSP, but you're now saying that the BSP can change
> it. If so, then please point exactly the flaw in the explanation in
> that mail.

Frankly, I have explained these details in commit message and previous
version patch[1] with print messages on the code.

BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
bpp/lanes and it indeed depends on PLL computation (not tcon_div),
anyway I have explained again on this initial link you mentioned.
Please have a look and get back.

[1] https://patchwork.freedesktop.org/patch/291525/
  

On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> >
> > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > MIPI clock topology in Allwinner DSI controller.
> > >
> > > TCON dotclock driver is computing the desired DCLK divider based on
> > > panel pixel clock along with input DCLK min, max divider values from
> > > tcon driver and that would eventually set the pll-mipi clock rate.
> > >
> > > The current code is passing dsi min and max divider value as 4 via
> > > tcon driver which would ended-up triggering below vblank wait timed out
> > > warning on "bananapi,s070wv20-ct16" panel.
> > >
> > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > >  [CRTC:46:crtc-0] vblank wait timed out
> > >  Modules linked in:
> > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > >  Hardware name: Allwinner sun8i Family
> > >  Workqueue: events deferred_probe_work_func
> > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > >  9fa0:                                     00000000 00000000 00000000 00000000
> > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > >  ---[ end trace 4017fea4906ab391 ]---
> > >
> > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > >
> > > Which would compute the pll_freq and set a clock rate for it in
> > > [3] and [4] respectively.
> > >
> > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > and got fixed with this computation logic 'format/lanes', so this patch
> > > using dclk min and max dividers as per BSP.
> > >
> > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> >
> > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> >
> > The only reply you've sent is that you indeed see that the divider is
> > set to 4 in the BSP, but you're now saying that the BSP can change
> > it. If so, then please point exactly the flaw in the explanation in
> > that mail.
>
> Frankly, I have explained these details in commit message and previous
> version patch[1] with print messages on the code.
>
> BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> anyway I have explained again on this initial link you mentioned.
> Please have a look and get back.

I'll have a look, thanks.

I've given your patches a try on my setup though, and this patch
breaks it with vblank timeouts and some horizontal lines that looks
like what should be displayed, but blinking and on the right of the
display. The previous ones are fine though.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
  

On Tue, Jun 4, 2019 at 8:00 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> > On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > >
> > > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > > MIPI clock topology in Allwinner DSI controller.
> > > >
> > > > TCON dotclock driver is computing the desired DCLK divider based on
> > > > panel pixel clock along with input DCLK min, max divider values from
> > > > tcon driver and that would eventually set the pll-mipi clock rate.
> > > >
> > > > The current code is passing dsi min and max divider value as 4 via
> > > > tcon driver which would ended-up triggering below vblank wait timed out
> > > > warning on "bananapi,s070wv20-ct16" panel.
> > > >
> > > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > > >  [CRTC:46:crtc-0] vblank wait timed out
> > > >  Modules linked in:
> > > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > > >  Hardware name: Allwinner sun8i Family
> > > >  Workqueue: events deferred_probe_work_func
> > > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > > >  9fa0:                                     00000000 00000000 00000000 00000000
> > > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > > >  ---[ end trace 4017fea4906ab391 ]---
> > > >
> > > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > > >
> > > > Which would compute the pll_freq and set a clock rate for it in
> > > > [3] and [4] respectively.
> > > >
> > > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > > and got fixed with this computation logic 'format/lanes', so this patch
> > > > using dclk min and max dividers as per BSP.
> > > >
> > > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> > >
> > > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> > >
> > > The only reply you've sent is that you indeed see that the divider is
> > > set to 4 in the BSP, but you're now saying that the BSP can change
> > > it. If so, then please point exactly the flaw in the explanation in
> > > that mail.
> >
> > Frankly, I have explained these details in commit message and previous
> > version patch[1] with print messages on the code.
> >
> > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > anyway I have explained again on this initial link you mentioned.
> > Please have a look and get back.
>
> I'll have a look, thanks.
>
> I've given your patches a try on my setup though, and this patch
> breaks it with vblank timeouts and some horizontal lines that looks
> like what should be displayed, but blinking and on the right of the
> display. The previous ones are fine though.

Would you please send me the link of panel driver.
  

On Wed, Jun 05, 2019 at 01:11:44PM +0530, Jagan Teki wrote:
> On Tue, Jun 4, 2019 at 8:00 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> >
> > On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> > > On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > >
> > > > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > > > MIPI clock topology in Allwinner DSI controller.
> > > > >
> > > > > TCON dotclock driver is computing the desired DCLK divider based on
> > > > > panel pixel clock along with input DCLK min, max divider values from
> > > > > tcon driver and that would eventually set the pll-mipi clock rate.
> > > > >
> > > > > The current code is passing dsi min and max divider value as 4 via
> > > > > tcon driver which would ended-up triggering below vblank wait timed out
> > > > > warning on "bananapi,s070wv20-ct16" panel.
> > > > >
> > > > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > > > >  [CRTC:46:crtc-0] vblank wait timed out
> > > > >  Modules linked in:
> > > > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > > > >  Hardware name: Allwinner sun8i Family
> > > > >  Workqueue: events deferred_probe_work_func
> > > > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > > > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > > > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > > > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > > > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > > > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > > > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > > > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > > > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > > > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > > > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > > > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > > > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > > > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > > > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > > > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > > > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > > > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > > > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > > > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > > > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > > > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > > > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > > > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > > > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > > > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > > > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > > > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > > > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > > > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > > > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > > > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > > > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > > > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > > > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > > > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > > > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > > > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > > > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > > > >  9fa0:                                     00000000 00000000 00000000 00000000
> > > > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > > > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > > > >  ---[ end trace 4017fea4906ab391 ]---
> > > > >
> > > > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > > > >
> > > > > Which would compute the pll_freq and set a clock rate for it in
> > > > > [3] and [4] respectively.
> > > > >
> > > > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > > > and got fixed with this computation logic 'format/lanes', so this patch
> > > > > using dclk min and max dividers as per BSP.
> > > > >
> > > > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> > > >
> > > > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> > > >
> > > > The only reply you've sent is that you indeed see that the divider is
> > > > set to 4 in the BSP, but you're now saying that the BSP can change
> > > > it. If so, then please point exactly the flaw in the explanation in
> > > > that mail.
> > >
> > > Frankly, I have explained these details in commit message and previous
> > > version patch[1] with print messages on the code.
> > >
> > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > anyway I have explained again on this initial link you mentioned.
> > > Please have a look and get back.
> >
> > I'll have a look, thanks.
> >
> > I've given your patches a try on my setup though, and this patch
> > breaks it with vblank timeouts and some horizontal lines that looks
> > like what should be displayed, but blinking and on the right of the
> > display. The previous ones are fine though.
>
> Would you please send me the link of panel driver.

It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c

Maximey

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
  

On Thu, Jun 13, 2019 at 7:28 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Wed, Jun 05, 2019 at 01:11:44PM +0530, Jagan Teki wrote:
> > On Tue, Jun 4, 2019 at 8:00 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > >
> > > On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> > > > On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > >
> > > > > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > > > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > > > > MIPI clock topology in Allwinner DSI controller.
> > > > > >
> > > > > > TCON dotclock driver is computing the desired DCLK divider based on
> > > > > > panel pixel clock along with input DCLK min, max divider values from
> > > > > > tcon driver and that would eventually set the pll-mipi clock rate.
> > > > > >
> > > > > > The current code is passing dsi min and max divider value as 4 via
> > > > > > tcon driver which would ended-up triggering below vblank wait timed out
> > > > > > warning on "bananapi,s070wv20-ct16" panel.
> > > > > >
> > > > > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > > > > >  [CRTC:46:crtc-0] vblank wait timed out
> > > > > >  Modules linked in:
> > > > > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > > > > >  Hardware name: Allwinner sun8i Family
> > > > > >  Workqueue: events deferred_probe_work_func
> > > > > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > > > > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > > > > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > > > > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > > > > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > > > > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > > > > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > > > > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > > > > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > > > > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > > > > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > > > > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > > > > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > > > > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > > > > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > > > > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > > > > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > > > > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > > > > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > > > > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > > > > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > > > > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > > > > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > > > > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > > > > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > > > > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > > > > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > > > > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > > > > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > > > > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > > > > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > > > > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > > > > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > > > > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > > > > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > > > > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > > > > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > > > > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > > > > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > > > > >  9fa0:                                     00000000 00000000 00000000 00000000
> > > > > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > > > > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > > > > >  ---[ end trace 4017fea4906ab391 ]---
> > > > > >
> > > > > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > > > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > > > > >
> > > > > > Which would compute the pll_freq and set a clock rate for it in
> > > > > > [3] and [4] respectively.
> > > > > >
> > > > > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > > > > and got fixed with this computation logic 'format/lanes', so this patch
> > > > > > using dclk min and max dividers as per BSP.
> > > > > >
> > > > > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > > > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > > > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > > > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> > > > >
> > > > > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> > > > >
> > > > > The only reply you've sent is that you indeed see that the divider is
> > > > > set to 4 in the BSP, but you're now saying that the BSP can change
> > > > > it. If so, then please point exactly the flaw in the explanation in
> > > > > that mail.
> > > >
> > > > Frankly, I have explained these details in commit message and previous
> > > > version patch[1] with print messages on the code.
> > > >
> > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > anyway I have explained again on this initial link you mentioned.
> > > > Please have a look and get back.
> > >
> > > I'll have a look, thanks.
> > >
> > > I've given your patches a try on my setup though, and this patch
> > > breaks it with vblank timeouts and some horizontal lines that looks
> > > like what should be displayed, but blinking and on the right of the
> > > display. The previous ones are fine though.
> >
> > Would you please send me the link of panel driver.
>
> It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c

Look like this panel work even w/o any vendor sequence. it's similar
to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
working with this divider?
  

On Fri, Jun 14, 2019 at 05:33:23PM +0530, Jagan Teki wrote:
> On Thu, Jun 13, 2019 at 7:28 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> >
> > On Wed, Jun 05, 2019 at 01:11:44PM +0530, Jagan Teki wrote:
> > > On Tue, Jun 4, 2019 at 8:00 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > >
> > > > On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> > > > > On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > >
> > > > > > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > > > > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > > > > > MIPI clock topology in Allwinner DSI controller.
> > > > > > >
> > > > > > > TCON dotclock driver is computing the desired DCLK divider based on
> > > > > > > panel pixel clock along with input DCLK min, max divider values from
> > > > > > > tcon driver and that would eventually set the pll-mipi clock rate.
> > > > > > >
> > > > > > > The current code is passing dsi min and max divider value as 4 via
> > > > > > > tcon driver which would ended-up triggering below vblank wait timed out
> > > > > > > warning on "bananapi,s070wv20-ct16" panel.
> > > > > > >
> > > > > > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > > > > > >  [CRTC:46:crtc-0] vblank wait timed out
> > > > > > >  Modules linked in:
> > > > > > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > > > > > >  Hardware name: Allwinner sun8i Family
> > > > > > >  Workqueue: events deferred_probe_work_func
> > > > > > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > > > > > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > > > > > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > > > > > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > > > > > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > > > > > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > > > > > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > > > > > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > > > > > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > > > > > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > > > > > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > > > > > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > > > > > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > > > > > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > > > > > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > > > > > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > > > > > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > > > > > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > > > > > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > > > > > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > > > > > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > > > > > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > > > > > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > > > > > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > > > > > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > > > > > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > > > > > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > > > > > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > > > > > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > > > > > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > > > > > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > > > > > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > > > > > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > > > > > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > > > > > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > > > > > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > > > > > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > > > > > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > > > > > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > > > > > >  9fa0:                                     00000000 00000000 00000000 00000000
> > > > > > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > > > > > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > > > > > >  ---[ end trace 4017fea4906ab391 ]---
> > > > > > >
> > > > > > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > > > > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > > > > > >
> > > > > > > Which would compute the pll_freq and set a clock rate for it in
> > > > > > > [3] and [4] respectively.
> > > > > > >
> > > > > > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > > > > > and got fixed with this computation logic 'format/lanes', so this patch
> > > > > > > using dclk min and max dividers as per BSP.
> > > > > > >
> > > > > > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > > > > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > > > > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > > > > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> > > > > >
> > > > > > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> > > > > >
> > > > > > The only reply you've sent is that you indeed see that the divider is
> > > > > > set to 4 in the BSP, but you're now saying that the BSP can change
> > > > > > it. If so, then please point exactly the flaw in the explanation in
> > > > > > that mail.
> > > > >
> > > > > Frankly, I have explained these details in commit message and previous
> > > > > version patch[1] with print messages on the code.
> > > > >
> > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > anyway I have explained again on this initial link you mentioned.
> > > > > Please have a look and get back.
> > > >
> > > > I'll have a look, thanks.
> > > >
> > > > I've given your patches a try on my setup though, and this patch
> > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > like what should be displayed, but blinking and on the right of the
> > > > display. The previous ones are fine though.
> > >
> > > Would you please send me the link of panel driver.
> >
> > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
>
> Look like this panel work even w/o any vendor sequence. it's similar
> to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> working with this divider?

It works with 4, it doesn't work with 6.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
  

On Mon, Jun 24, 2019 at 6:34 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Fri, Jun 14, 2019 at 05:33:23PM +0530, Jagan Teki wrote:
> > On Thu, Jun 13, 2019 at 7:28 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > >
> > > On Wed, Jun 05, 2019 at 01:11:44PM +0530, Jagan Teki wrote:
> > > > On Tue, Jun 4, 2019 at 8:00 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > >
> > > > > On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> > > > > > On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > > >
> > > > > > > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > > > > > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > > > > > > MIPI clock topology in Allwinner DSI controller.
> > > > > > > >
> > > > > > > > TCON dotclock driver is computing the desired DCLK divider based on
> > > > > > > > panel pixel clock along with input DCLK min, max divider values from
> > > > > > > > tcon driver and that would eventually set the pll-mipi clock rate.
> > > > > > > >
> > > > > > > > The current code is passing dsi min and max divider value as 4 via
> > > > > > > > tcon driver which would ended-up triggering below vblank wait timed out
> > > > > > > > warning on "bananapi,s070wv20-ct16" panel.
> > > > > > > >
> > > > > > > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > > > > > > >  [CRTC:46:crtc-0] vblank wait timed out
> > > > > > > >  Modules linked in:
> > > > > > > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > > > > > > >  Hardware name: Allwinner sun8i Family
> > > > > > > >  Workqueue: events deferred_probe_work_func
> > > > > > > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > > > > > > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > > > > > > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > > > > > > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > > > > > > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > > > > > > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > > > > > > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > > > > > > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > > > > > > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > > > > > > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > > > > > > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > > > > > > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > > > > > > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > > > > > > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > > > > > > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > > > > > > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > > > > > > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > > > > > > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > > > > > > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > > > > > > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > > > > > > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > > > > > > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > > > > > > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > > > > > > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > > > > > > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > > > > > > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > > > > > > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > > > > > > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > > > > > > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > > > > > > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > > > > > > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > > > > > > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > > > > > > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > > > > > > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > > > > > > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > > > > > > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > > > > > > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > > > > > > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > > > > > > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > > > > > > >  9fa0:                                     00000000 00000000 00000000 00000000
> > > > > > > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > > > > > > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > > > > > > >  ---[ end trace 4017fea4906ab391 ]---
> > > > > > > >
> > > > > > > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > > > > > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > > > > > > >
> > > > > > > > Which would compute the pll_freq and set a clock rate for it in
> > > > > > > > [3] and [4] respectively.
> > > > > > > >
> > > > > > > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > > > > > > and got fixed with this computation logic 'format/lanes', so this patch
> > > > > > > > using dclk min and max dividers as per BSP.
> > > > > > > >
> > > > > > > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > > > > > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > > > > > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > > > > > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> > > > > > >
> > > > > > > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > > > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> > > > > > >
> > > > > > > The only reply you've sent is that you indeed see that the divider is
> > > > > > > set to 4 in the BSP, but you're now saying that the BSP can change
> > > > > > > it. If so, then please point exactly the flaw in the explanation in
> > > > > > > that mail.
> > > > > >
> > > > > > Frankly, I have explained these details in commit message and previous
> > > > > > version patch[1] with print messages on the code.
> > > > > >
> > > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > > anyway I have explained again on this initial link you mentioned.
> > > > > > Please have a look and get back.
> > > > >
> > > > > I'll have a look, thanks.
> > > > >
> > > > > I've given your patches a try on my setup though, and this patch
> > > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > > like what should be displayed, but blinking and on the right of the
> > > > > display. The previous ones are fine though.
> > > >
> > > > Would you please send me the link of panel driver.
> > >
> > > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
> >
> > Look like this panel work even w/o any vendor sequence. it's similar
> > to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> > working with this divider?
>
> It works with 4, it doesn't work with 6.

Can be the pixel clock with associated timings can make this diff.
Would you send me the pixel clock, pll_rate and timings this panel
used it from BSP?
  

On Mon, Jun 24, 2019 at 09:32:11PM +0530, Jagan Teki wrote:
> On Mon, Jun 24, 2019 at 6:34 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> >
> > On Fri, Jun 14, 2019 at 05:33:23PM +0530, Jagan Teki wrote:
> > > On Thu, Jun 13, 2019 at 7:28 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > >
> > > > On Wed, Jun 05, 2019 at 01:11:44PM +0530, Jagan Teki wrote:
> > > > > On Tue, Jun 4, 2019 at 8:00 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > >
> > > > > > On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> > > > > > > On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > > > >
> > > > > > > > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > > > > > > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > > > > > > > MIPI clock topology in Allwinner DSI controller.
> > > > > > > > >
> > > > > > > > > TCON dotclock driver is computing the desired DCLK divider based on
> > > > > > > > > panel pixel clock along with input DCLK min, max divider values from
> > > > > > > > > tcon driver and that would eventually set the pll-mipi clock rate.
> > > > > > > > >
> > > > > > > > > The current code is passing dsi min and max divider value as 4 via
> > > > > > > > > tcon driver which would ended-up triggering below vblank wait timed out
> > > > > > > > > warning on "bananapi,s070wv20-ct16" panel.
> > > > > > > > >
> > > > > > > > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > > > > > > > >  [CRTC:46:crtc-0] vblank wait timed out
> > > > > > > > >  Modules linked in:
> > > > > > > > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > > > > > > > >  Hardware name: Allwinner sun8i Family
> > > > > > > > >  Workqueue: events deferred_probe_work_func
> > > > > > > > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > > > > > > > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > > > > > > > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > > > > > > > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > > > > > > > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > > > > > > > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > > > > > > > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > > > > > > > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > > > > > > > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > > > > > > > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > > > > > > > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > > > > > > > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > > > > > > > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > > > > > > > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > > > > > > > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > > > > > > > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > > > > > > > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > > > > > > > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > > > > > > > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > > > > > > > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > > > > > > > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > > > > > > > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > > > > > > > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > > > > > > > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > > > > > > > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > > > > > > > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > > > > > > > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > > > > > > > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > > > > > > > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > > > > > > > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > > > > > > > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > > > > > > > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > > > > > > > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > > > > > > > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > > > > > > > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > > > > > > > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > > > > > > > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > > > > > > > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > > > > > > > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > > > > > > > >  9fa0:                                     00000000 00000000 00000000 00000000
> > > > > > > > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > > > > > > > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > > > > > > > >  ---[ end trace 4017fea4906ab391 ]---
> > > > > > > > >
> > > > > > > > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > > > > > > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > > > > > > > >
> > > > > > > > > Which would compute the pll_freq and set a clock rate for it in
> > > > > > > > > [3] and [4] respectively.
> > > > > > > > >
> > > > > > > > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > > > > > > > and got fixed with this computation logic 'format/lanes', so this patch
> > > > > > > > > using dclk min and max dividers as per BSP.
> > > > > > > > >
> > > > > > > > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > > > > > > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > > > > > > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > > > > > > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> > > > > > > >
> > > > > > > > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > > > > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> > > > > > > >
> > > > > > > > The only reply you've sent is that you indeed see that the divider is
> > > > > > > > set to 4 in the BSP, but you're now saying that the BSP can change
> > > > > > > > it. If so, then please point exactly the flaw in the explanation in
> > > > > > > > that mail.
> > > > > > >
> > > > > > > Frankly, I have explained these details in commit message and previous
> > > > > > > version patch[1] with print messages on the code.
> > > > > > >
> > > > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > > > anyway I have explained again on this initial link you mentioned.
> > > > > > > Please have a look and get back.
> > > > > >
> > > > > > I'll have a look, thanks.
> > > > > >
> > > > > > I've given your patches a try on my setup though, and this patch
> > > > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > > > like what should be displayed, but blinking and on the right of the
> > > > > > display. The previous ones are fine though.
> > > > >
> > > > > Would you please send me the link of panel driver.
> > > >
> > > > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
> > >
> > > Look like this panel work even w/o any vendor sequence. it's similar
> > > to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> > > working with this divider?
> >
> > It works with 4, it doesn't work with 6.
>
> Can be the pixel clock with associated timings can make this diff.
> Would you send me the pixel clock, pll_rate and timings this panel
> used it from BSP?

This board never had an Allwinner BSP

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
  

On Tue, Jun 25, 2019 at 8:07 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Mon, Jun 24, 2019 at 09:32:11PM +0530, Jagan Teki wrote:
> > On Mon, Jun 24, 2019 at 6:34 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > >
> > > On Fri, Jun 14, 2019 at 05:33:23PM +0530, Jagan Teki wrote:
> > > > On Thu, Jun 13, 2019 at 7:28 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > >
> > > > > On Wed, Jun 05, 2019 at 01:11:44PM +0530, Jagan Teki wrote:
> > > > > > On Tue, Jun 4, 2019 at 8:00 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > > >
> > > > > > > On Fri, May 24, 2019 at 03:37:36PM +0530, Jagan Teki wrote:
> > > > > > > > On Fri, May 24, 2019 at 2:18 AM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > > > > >
> > > > > > > > > On Mon, May 20, 2019 at 02:33:11PM +0530, Jagan Teki wrote:
> > > > > > > > > > pll-video => pll-mipi => tcon0 => tcon0-pixel-clock is the typical
> > > > > > > > > > MIPI clock topology in Allwinner DSI controller.
> > > > > > > > > >
> > > > > > > > > > TCON dotclock driver is computing the desired DCLK divider based on
> > > > > > > > > > panel pixel clock along with input DCLK min, max divider values from
> > > > > > > > > > tcon driver and that would eventually set the pll-mipi clock rate.
> > > > > > > > > >
> > > > > > > > > > The current code is passing dsi min and max divider value as 4 via
> > > > > > > > > > tcon driver which would ended-up triggering below vblank wait timed out
> > > > > > > > > > warning on "bananapi,s070wv20-ct16" panel.
> > > > > > > > > >
> > > > > > > > > >  WARNING: CPU: 0 PID: 31 at drivers/gpu/drm/drm_atomic_helper.c:1429 drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0
> > > > > > > > > >  [CRTC:46:crtc-0] vblank wait timed out
> > > > > > > > > >  Modules linked in:
> > > > > > > > > >  CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 5.1.0-next-20190514-00025-g5186cdf10757-dirty #6
> > > > > > > > > >  Hardware name: Allwinner sun8i Family
> > > > > > > > > >  Workqueue: events deferred_probe_work_func
> > > > > > > > > >  [<c010ed54>] (unwind_backtrace) from [<c010b76c>] (show_stack+0x10/0x14)
> > > > > > > > > >  [<c010b76c>] (show_stack) from [<c0688c70>] (dump_stack+0x84/0x98)
> > > > > > > > > >  [<c0688c70>] (dump_stack) from [<c011d9e4>] (__warn+0xfc/0x114)
> > > > > > > > > >  [<c011d9e4>] (__warn) from [<c011da40>] (warn_slowpath_fmt+0x44/0x68)
> > > > > > > > > >  [<c011da40>] (warn_slowpath_fmt) from [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1+0x298/0x2a0)
> > > > > > > > > >  [<c040cd50>] (drm_atomic_helper_wait_for_vblanks.part.1) from [<c040e694>] (drm_atomic_helper_commit_tail_rpm+0x5c/0x6c)
> > > > > > > > > >  [<c040e694>] (drm_atomic_helper_commit_tail_rpm) from [<c040e4dc>] (commit_tail+0x40/0x6c)
> > > > > > > > > >  [<c040e4dc>] (commit_tail) from [<c040e5cc>] (drm_atomic_helper_commit+0xbc/0x128)
> > > > > > > > > >  [<c040e5cc>] (drm_atomic_helper_commit) from [<c0411b64>] (restore_fbdev_mode_atomic+0x1cc/0x1dc)
> > > > > > > > > >  [<c0411b64>] (restore_fbdev_mode_atomic) from [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xa0)
> > > > > > > > > >  [<c04156f8>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c0415774>] (drm_fb_helper_set_par+0x30/0x54)
> > > > > > > > > >  [<c0415774>] (drm_fb_helper_set_par) from [<c03ad450>] (fbcon_init+0x560/0x5ac)
> > > > > > > > > >  [<c03ad450>] (fbcon_init) from [<c03eb8a0>] (visual_init+0xbc/0x104)
> > > > > > > > > >  [<c03eb8a0>] (visual_init) from [<c03ed1b8>] (do_bind_con_driver+0x1b0/0x390)
> > > > > > > > > >  [<c03ed1b8>] (do_bind_con_driver) from [<c03ed780>] (do_take_over_console+0x13c/0x1c4)
> > > > > > > > > >  [<c03ed780>] (do_take_over_console) from [<c03ad800>] (do_fbcon_takeover+0x74/0xcc)
> > > > > > > > > >  [<c03ad800>] (do_fbcon_takeover) from [<c013c9c8>] (notifier_call_chain+0x44/0x84)
> > > > > > > > > >  [<c013c9c8>] (notifier_call_chain) from [<c013cd20>] (__blocking_notifier_call_chain+0x48/0x60)
> > > > > > > > > >  [<c013cd20>] (__blocking_notifier_call_chain) from [<c013cd50>] (blocking_notifier_call_chain+0x18/0x20)
> > > > > > > > > >  [<c013cd50>] (blocking_notifier_call_chain) from [<c03a6e44>] (register_framebuffer+0x1e0/0x2f8)
> > > > > > > > > >  [<c03a6e44>] (register_framebuffer) from [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock+0x2fc/0x50c)
> > > > > > > > > >  [<c04153c0>] (__drm_fb_helper_initial_config_and_unlock) from [<c04158c8>] (drm_fbdev_client_hotplug+0xe8/0x1b8)
> > > > > > > > > >  [<c04158c8>] (drm_fbdev_client_hotplug) from [<c0415a20>] (drm_fbdev_generic_setup+0x88/0x118)
> > > > > > > > > >  [<c0415a20>] (drm_fbdev_generic_setup) from [<c043f060>] (sun4i_drv_bind+0x128/0x160)
> > > > > > > > > >  [<c043f060>] (sun4i_drv_bind) from [<c044b588>] (try_to_bring_up_master+0x164/0x1a0)
> > > > > > > > > >  [<c044b588>] (try_to_bring_up_master) from [<c044b658>] (__component_add+0x94/0x140)
> > > > > > > > > >  [<c044b658>] (__component_add) from [<c0445e0c>] (sun6i_dsi_probe+0x144/0x234)
> > > > > > > > > >  [<c0445e0c>] (sun6i_dsi_probe) from [<c0452ee4>] (platform_drv_probe+0x48/0x9c)
> > > > > > > > > >  [<c0452ee4>] (platform_drv_probe) from [<c04512bc>] (really_probe+0x1dc/0x2c8)
> > > > > > > > > >  [<c04512bc>] (really_probe) from [<c0451508>] (driver_probe_device+0x60/0x160)
> > > > > > > > > >  [<c0451508>] (driver_probe_device) from [<c044f794>] (bus_for_each_drv+0x74/0xb8)
> > > > > > > > > >  [<c044f794>] (bus_for_each_drv) from [<c045106c>] (__device_attach+0xd0/0x13c)
> > > > > > > > > >  [<c045106c>] (__device_attach) from [<c0450464>] (bus_probe_device+0x84/0x8c)
> > > > > > > > > >  [<c0450464>] (bus_probe_device) from [<c04508f0>] (deferred_probe_work_func+0x64/0x90)
> > > > > > > > > >  [<c04508f0>] (deferred_probe_work_func) from [<c0135970>] (process_one_work+0x204/0x420)
> > > > > > > > > >  [<c0135970>] (process_one_work) from [<c013690c>] (worker_thread+0x274/0x5a0)
> > > > > > > > > >  [<c013690c>] (worker_thread) from [<c013b3d8>] (kthread+0x11c/0x14c)
> > > > > > > > > >  [<c013b3d8>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
> > > > > > > > > >  Exception stack(0xde539fb0 to 0xde539ff8)
> > > > > > > > > >  9fa0:                                     00000000 00000000 00000000 00000000
> > > > > > > > > >  9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> > > > > > > > > >  9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> > > > > > > > > >  ---[ end trace 4017fea4906ab391 ]---
> > > > > > > > > >
> > > > > > > > > > But accordingly to Allwinner A33, A64 BSP codes [1] [2] this divider
> > > > > > > > > > is clearly using 'format/lanes' for dsi divider value, dsi_clk.clk_div
> > > > > > > > > >
> > > > > > > > > > Which would compute the pll_freq and set a clock rate for it in
> > > > > > > > > > [3] and [4] respectively.
> > > > > > > > > >
> > > > > > > > > > The same issue has reproduced in A33, A64 with 4-lane and 2-lane devices
> > > > > > > > > > and got fixed with this computation logic 'format/lanes', so this patch
> > > > > > > > > > using dclk min and max dividers as per BSP.
> > > > > > > > > >
> > > > > > > > > > [1] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1106
> > > > > > > > > > [2] https://github.com/BPI-SINOVOIP/BPI-M64-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/disp_al.c#L213
> > > > > > > > > > [3] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1127
> > > > > > > > > > [4] https://github.com/BPI-SINOVOIP/BPI-M2M-bsp/blob/master/linux-sunxi/drivers/video/sunxi/disp/de/disp_lcd.c#L1161
> > > > > > > > >
> > > > > > > > > In that mail, I've pointed out that clk_div isn't used for the TCON dclk divider:
> > > > > > > > > http://lists.infradead.org/pipermail/linux-arm-kernel/2019-February/629596.html
> > > > > > > > >
> > > > > > > > > The only reply you've sent is that you indeed see that the divider is
> > > > > > > > > set to 4 in the BSP, but you're now saying that the BSP can change
> > > > > > > > > it. If so, then please point exactly the flaw in the explanation in
> > > > > > > > > that mail.
> > > > > > > >
> > > > > > > > Frankly, I have explained these details in commit message and previous
> > > > > > > > version patch[1] with print messages on the code.
> > > > > > > >
> > > > > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > > > > anyway I have explained again on this initial link you mentioned.
> > > > > > > > Please have a look and get back.
> > > > > > >
> > > > > > > I'll have a look, thanks.
> > > > > > >
> > > > > > > I've given your patches a try on my setup though, and this patch
> > > > > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > > > > like what should be displayed, but blinking and on the right of the
> > > > > > > display. The previous ones are fine though.
> > > > > >
> > > > > > Would you please send me the link of panel driver.
> > > > >
> > > > > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
> > > >
> > > > Look like this panel work even w/o any vendor sequence. it's similar
> > > > to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> > > > working with this divider?
> > >
> > > It works with 4, it doesn't work with 6.
> >
> > Can be the pixel clock with associated timings can make this diff.
> > Would you send me the pixel clock, pll_rate and timings this panel
> > used it from BSP?
>
> This board never had an Allwinner BSP

Running on BSP would help to understand some clue, anyway would you
send me the the value PLL_MIPI register (devme 0x1c20040) on this
board. I'm trying to understand how it value in your case.
  

On Tue, Jul 02, 2019 at 12:30:14AM +0530, Jagan Teki wrote:
> On Tue, Jun 25, 2019 at 8:07 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > > > > > anyway I have explained again on this initial link you mentioned.
> > > > > > > > > Please have a look and get back.
> > > > > > > >
> > > > > > > > I'll have a look, thanks.
> > > > > > > >
> > > > > > > > I've given your patches a try on my setup though, and this patch
> > > > > > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > > > > > like what should be displayed, but blinking and on the right of the
> > > > > > > > display. The previous ones are fine though.
> > > > > > >
> > > > > > > Would you please send me the link of panel driver.
> > > > > >
> > > > > > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
> > > > >
> > > > > Look like this panel work even w/o any vendor sequence. it's similar
> > > > > to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> > > > > working with this divider?
> > > >
> > > > It works with 4, it doesn't work with 6.
> > >
> > > Can be the pixel clock with associated timings can make this diff.
> > > Would you send me the pixel clock, pll_rate and timings this panel
> > > used it from BSP?
> >
> > This board never had an Allwinner BSP
>
> Running on BSP would help to understand some clue, anyway would you
> send me the the value PLL_MIPI register (devme 0x1c20040) on this
> board. I'm trying to understand how it value in your case.

I'm sorry, but I'm not going to port a whole BSP on that board,
especially for something I haven't been convinced it's the right fix.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
  

On Tue, Jul 2, 2019 at 8:59 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Tue, Jul 02, 2019 at 12:30:14AM +0530, Jagan Teki wrote:
> > On Tue, Jun 25, 2019 at 8:07 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > > > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > > > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > > > > > > anyway I have explained again on this initial link you mentioned.
> > > > > > > > > > Please have a look and get back.
> > > > > > > > >
> > > > > > > > > I'll have a look, thanks.
> > > > > > > > >
> > > > > > > > > I've given your patches a try on my setup though, and this patch
> > > > > > > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > > > > > > like what should be displayed, but blinking and on the right of the
> > > > > > > > > display. The previous ones are fine though.
> > > > > > > >
> > > > > > > > Would you please send me the link of panel driver.
> > > > > > >
> > > > > > > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
> > > > > >
> > > > > > Look like this panel work even w/o any vendor sequence. it's similar
> > > > > > to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> > > > > > working with this divider?
> > > > >
> > > > > It works with 4, it doesn't work with 6.
> > > >
> > > > Can be the pixel clock with associated timings can make this diff.
> > > > Would you send me the pixel clock, pll_rate and timings this panel
> > > > used it from BSP?
> > >
> > > This board never had an Allwinner BSP
> >
> > Running on BSP would help to understand some clue, anyway would you
> > send me the the value PLL_MIPI register (devme 0x1c20040) on this
> > board. I'm trying to understand how it value in your case.
>
> I'm sorry, but I'm not going to port a whole BSP on that board,
> especially for something I haven't been convinced it's the right fix.

Look like a dead lock here, this change has a conclusive evidence from
BSP (which is AW datasheet or open code to outside world) and it is
working with A33, A64 and R40 which was tested in 4 different panels
and I don't understand the reason for not going with this (atleast
check with respect to BSP).

Please suggest, what I can do further, your suggestion is very helpful here.

Jagan.
  

On Tue, Jul 02, 2019 at 09:10:26PM +0530, Jagan Teki wrote:
> On Tue, Jul 2, 2019 at 8:59 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > On Tue, Jul 02, 2019 at 12:30:14AM +0530, Jagan Teki wrote:
> > > On Tue, Jun 25, 2019 at 8:07 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> > > > > > > > > > > BSP has tcon_div and dsi_div. dsi_div is dynamic which depends on
> > > > > > > > > > > bpp/lanes and it indeed depends on PLL computation (not tcon_div),
> > > > > > > > > > > anyway I have explained again on this initial link you mentioned.
> > > > > > > > > > > Please have a look and get back.
> > > > > > > > > >
> > > > > > > > > > I'll have a look, thanks.
> > > > > > > > > >
> > > > > > > > > > I've given your patches a try on my setup though, and this patch
> > > > > > > > > > breaks it with vblank timeouts and some horizontal lines that looks
> > > > > > > > > > like what should be displayed, but blinking and on the right of the
> > > > > > > > > > display. The previous ones are fine though.
> > > > > > > > >
> > > > > > > > > Would you please send me the link of panel driver.
> > > > > > > >
> > > > > > > > It's drivers/gpu/drm/panel/panel-ronbo-rb070d30.c
> > > > > > >
> > > > > > > Look like this panel work even w/o any vendor sequence. it's similar
> > > > > > > to the 4-lane panel I have with RGB888, so the dclk div is 6, is it
> > > > > > > working with this divider?
> > > > > >
> > > > > > It works with 4, it doesn't work with 6.
> > > > >
> > > > > Can be the pixel clock with associated timings can make this diff.
> > > > > Would you send me the pixel clock, pll_rate and timings this panel
> > > > > used it from BSP?
> > > >
> > > > This board never had an Allwinner BSP
> > >
> > > Running on BSP would help to understand some clue, anyway would you
> > > send me the the value PLL_MIPI register (devme 0x1c20040) on this
> > > board. I'm trying to understand how it value in your case.
> >
> > I'm sorry, but I'm not going to port a whole BSP on that board,
> > especially for something I haven't been convinced it's the right fix.
>
> Look like a dead lock here, this change has a conclusive evidence from
> BSP (which is AW datasheet or open code to outside world) and it is
> working with A33, A64 and R40 which was tested in 4 different panels
> and I don't understand the reason for not going with this (atleast
> check with respect to BSP).

Because that would take a month or so?

> Please suggest, what I can do further, your suggestion is very
> helpful here.

I already did, and you ignored it. Several times.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com