[10/10] drm/mxsfb: stop controller and drain FIFOs if already initialized
diff mbox series

Message ID 20240903153157.918185-10-dario.binacchi@amarulasolutions.com
State New
Headers show
Series
  • [01/10] pmdomain: core: fix "sd_count" field setting
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Commit Message

Dario Binacchi Sept. 3, 2024, 3:31 p.m. UTC 
You can't re-program the controller if it is still running. This may
lead to shifted pictures (FIFO issue?), so stop the controller and drain
its FIFOs in case it's already properly setup.
This patch is crucial when supporting the simple framebuffer, as the
controller has already been initialized by the bootloader.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---
 drivers/gpu/drm/mxsfb/mxsfb_drv.c |  3 +++
 drivers/gpu/drm/mxsfb/mxsfb_drv.h |  1 +
 drivers/gpu/drm/mxsfb/mxsfb_kms.c | 24 +++++++++++++++++++-----
 3 files changed, 23 insertions(+), 5 deletions(-)

Patch
diff mbox series 

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
index 1d8dcfd629e1..408b7a113906 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
@@ -10,6 +10,7 @@ 
 
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
+#include <linux/of.h>
 #include <linux/io.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
@@ -222,6 +223,8 @@  static int mxsfb_load(struct drm_device *drm,
 	if (!mxsfb)
 		return -ENOMEM;
 
+	mxsfb->enabled =
+		of_property_read_bool(drm->dev->of_node, "fsl,boot-on");
 	mxsfb->drm = drm;
 	drm->dev_private = mxsfb;
 	mxsfb->devdata = devdata;
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.h b/drivers/gpu/drm/mxsfb/mxsfb_drv.h
index d160d921b25f..0f9ae4ce450c 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h
@@ -47,6 +47,7 @@  struct mxsfb_drm_private {
 	struct drm_bridge		*bridge;
 
 	bool				crc_active;
+	bool                            enabled;
 };
 
 static inline struct mxsfb_drm_private *
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
index 7ed2516b6de0..9b453b0100d1 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
@@ -202,9 +202,11 @@  static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
 	writel(reg, mxsfb->base + LCDC_CTRL1);
 
 	writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_SET);
+
+	mxsfb->enabled = true;
 }
 
-static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
+static void _mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 {
 	u32 reg;
 
@@ -221,6 +223,13 @@  static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 	reg &= ~VDCTRL4_SYNC_SIGNALS_ON;
 	writel(reg, mxsfb->base + LCDC_VDCTRL4);
 
+	mxsfb->enabled = false;
+}
+
+static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
+{
+	_mxsfb_disable_controller(mxsfb);
+
 	clk_disable_unprepare(mxsfb->clk);
 	if (mxsfb->clk_disp_axi)
 		clk_disable_unprepare(mxsfb->clk_disp_axi);
@@ -296,10 +305,14 @@  static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb,
 			     bus_flags);
 	DRM_DEV_DEBUG_DRIVER(drm->dev, "Mode flags: 0x%08X\n", m->flags);
 
-	/* Mandatory eLCDIF reset as per the Reference Manual */
-	err = mxsfb_reset_block(mxsfb);
-	if (err)
-		return;
+	if (mxsfb->enabled) {
+		_mxsfb_disable_controller(mxsfb);
+	} else {
+		/* Mandatory eLCDIF reset as per the Reference Manual */
+		err = mxsfb_reset_block(mxsfb);
+		if (err)
+			return;
+	}
 
 	mxsfb_set_formats(mxsfb, bus_format);
 
@@ -418,6 +431,7 @@  static void mxsfb_crtc_atomic_disable(struct drm_crtc *crtc,
 
 	mxsfb_disable_axi_clk(mxsfb);
 	pm_runtime_put_sync(drm->dev);
+	mxsfb->enabled = false;
 }
 
 static int mxsfb_crtc_enable_vblank(struct drm_crtc *crtc)