| Message ID | 20220614101751.3636028-1-dario.binacchi@amarulasolutions.com |
|---|---|
| State | New |
| Headers | show |
| Series |
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| Related | show |
On 14-06-22, 12:17, Dario Binacchi wrote: > Driver registration fails on SOC imx8mn as its supplier, the clock > control module, is not ready. Since platform_driver_probe(), as > reported by its description, is incompatible with deferred probing, > we have to use platform_driver_register(). > > Fixes: a580b8c5429a ("dmaengine: mxs-dma: add dma support for i.MX23/28") > Co-developed-by: Michael Trimarchi <michael@amarulasolutions.com> > Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com> > Cc: stable@vger.kernel.org > > --- > > Changes in v3: > - Restore __init in front of mxs_dma_init() definition. > > Changes in v2: > - Add the tag "Cc: stable@vger.kernel.org" in the sign-off area. > > drivers/dma/mxs-dma.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c > index 994fc4d2aca4..6e90540fedc4 100644 > --- a/drivers/dma/mxs-dma.c > +++ b/drivers/dma/mxs-dma.c > @@ -741,7 +741,7 @@ static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec, > ofdma->of_node); > } > > -static int __init mxs_dma_probe(struct platform_device *pdev) > +static int mxs_dma_probe(struct platform_device *pdev) why drop __init here, if there is a reason for that please split this change and document such reason... > { > struct device_node *np = pdev->dev.of_node; > const struct mxs_dma_type *dma_type; > @@ -839,10 +839,7 @@ static struct platform_driver mxs_dma_driver = { > .name = "mxs-dma", > .of_match_table = mxs_dma_dt_ids, > }, > + .probe = mxs_dma_probe, > }; > > -static int __init mxs_dma_module_init(void) > -{ > - return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe); > -} > -subsys_initcall(mxs_dma_module_init); > +module_platform_driver(mxs_dma_driver); > -- > 2.32.0
Hi Vinod, On Thu, Jun 16, 2022 at 06:58:43AM -0700, Vinod Koul wrote: > On 14-06-22, 12:17, Dario Binacchi wrote: > > Driver registration fails on SOC imx8mn as its supplier, the clock > > control module, is not ready. Since platform_driver_probe(), as > > reported by its description, is incompatible with deferred probing, > > we have to use platform_driver_register(). > > > > Fixes: a580b8c5429a ("dmaengine: mxs-dma: add dma support for i.MX23/28") > > Co-developed-by: Michael Trimarchi <michael@amarulasolutions.com> > > Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> > > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com> > > Cc: stable@vger.kernel.org > > > > --- > > > > Changes in v3: > > - Restore __init in front of mxs_dma_init() definition. > > > > Changes in v2: > > - Add the tag "Cc: stable@vger.kernel.org" in the sign-off area. > > > > drivers/dma/mxs-dma.c | 9 +++------ > > 1 file changed, 3 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c > > index 994fc4d2aca4..6e90540fedc4 100644 > > --- a/drivers/dma/mxs-dma.c > > +++ b/drivers/dma/mxs-dma.c > > @@ -741,7 +741,7 @@ static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec, > > ofdma->of_node); > > } > > > > -static int __init mxs_dma_probe(struct platform_device *pdev) > > +static int mxs_dma_probe(struct platform_device *pdev) > > why drop __init here, if there is a reason for that please split this > change and document such reason... The reason for dropping __init comes with this patch. With platform_driver_probe() the probe function is called only once, during init time. The problem with platform_driver_probe() is that the probe function will never be called again when it initially returns -EPROBE_DEFER. That's a problem for Dario: The clock is not yet available, the driver defers probe and will never be probed again when the clock is finally available. With platform_driver_register() to which this patch switches to the probe function can be called at any time, thus __init has to be removed. For what it's worth: Acked-by: Sascha Hauer <s.hauer@pengutronix.de> for this patch. Sascha > > > { > > struct device_node *np = pdev->dev.of_node; > > const struct mxs_dma_type *dma_type; > > @@ -839,10 +839,7 @@ static struct platform_driver mxs_dma_driver = { > > .name = "mxs-dma", > > .of_match_table = mxs_dma_dt_ids, > > }, > > + .probe = mxs_dma_probe, > > }; > > > > -static int __init mxs_dma_module_init(void) > > -{ > > - return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe); > > -} > > -subsys_initcall(mxs_dma_module_init); > > +module_platform_driver(mxs_dma_driver); > > -- > > 2.32.0 > > -- > ~Vinod >
diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c index 994fc4d2aca4..6e90540fedc4 100644 --- a/drivers/dma/mxs-dma.c +++ b/drivers/dma/mxs-dma.c @@ -741,7 +741,7 @@ static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec, ofdma->of_node); } -static int __init mxs_dma_probe(struct platform_device *pdev) +static int mxs_dma_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; const struct mxs_dma_type *dma_type; @@ -839,10 +839,7 @@ static struct platform_driver mxs_dma_driver = { .name = "mxs-dma", .of_match_table = mxs_dma_dt_ids, }, + .probe = mxs_dma_probe, }; -static int __init mxs_dma_module_init(void) -{ - return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe); -} -subsys_initcall(mxs_dma_module_init); +module_platform_driver(mxs_dma_driver);
Driver registration fails on SOC imx8mn as its supplier, the clock control module, is not ready. Since platform_driver_probe(), as reported by its description, is incompatible with deferred probing, we have to use platform_driver_register(). Fixes: a580b8c5429a ("dmaengine: mxs-dma: add dma support for i.MX23/28") Co-developed-by: Michael Trimarchi <michael@amarulasolutions.com> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com> Cc: stable@vger.kernel.org --- Changes in v3: - Restore __init in front of mxs_dma_init() definition. Changes in v2: - Add the tag "Cc: stable@vger.kernel.org" in the sign-off area. drivers/dma/mxs-dma.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)