| Message ID | 20230308073945.2336302-1-u.kleine-koenig@pengutronix.de |
|---|---|
| Headers | show |
| Series | backlight: Convert to platform remove callback returning void | expand |
On Wed, 08 Mar 2023, Uwe Kleine-König wrote: > The .remove() callback for a platform driver returns an int which makes > many driver authors wrongly assume it's possible to do error handling by > returning an error code. However the value returned is (mostly) ignored > and this typically results in resource leaks. To improve here there is a > quest to make the remove callback return void. In the first step of this > quest all drivers are converted to .remove_new() which already returns > void. > > Trivially convert this driver from always returning zero in the remove > callback to the void returning variant. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/video/backlight/cr_bllcd.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
On Wed, 08 Mar 2023, Uwe Kleine-König wrote: > The .remove() callback for a platform driver returns an int which makes > many driver authors wrongly assume it's possible to do error handling by > returning an error code. However the value returned is (mostly) ignored > and this typically results in resource leaks. To improve here there is a > quest to make the remove callback return void. In the first step of this > quest all drivers are converted to .remove_new() which already returns > void. > > Trivially convert this driver from always returning zero in the remove > callback to the void returning variant. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/video/backlight/hp680_bl.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
On Wed, 08 Mar 2023, Uwe Kleine-König wrote: > The .remove() callback for a platform driver returns an int which makes > many driver authors wrongly assume it's possible to do error handling by > returning an error code. However the value returned is (mostly) ignored > and this typically results in resource leaks. To improve here there is a > quest to make the remove callback return void. In the first step of this > quest all drivers are converted to .remove_new() which already returns > void. > > Trivially convert this driver from always returning zero in the remove > callback to the void returning variant. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/video/backlight/lm3533_bl.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
On Wed, 08 Mar 2023, Uwe Kleine-König wrote: > The .remove() callback for a platform driver returns an int which makes > many driver authors wrongly assume it's possible to do error handling by > returning an error code. However the value returned is (mostly) ignored > and this typically results in resource leaks. To improve here there is a > quest to make the remove callback return void. In the first step of this > quest all drivers are converted to .remove_new() which already returns > void. > > Trivially convert this driver from always returning zero in the remove > callback to the void returning variant. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/video/backlight/lp8788_bl.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
On Wed, 08 Mar 2023, Uwe Kleine-König wrote: > The .remove() callback for a platform driver returns an int which makes > many driver authors wrongly assume it's possible to do error handling by > returning an error code. However the value returned is (mostly) ignored > and this typically results in resource leaks. To improve here there is a > quest to make the remove callback return void. In the first step of this > quest all drivers are converted to .remove_new() which already returns > void. > > Trivially convert this driver from always returning zero in the remove > callback to the void returning variant. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/video/backlight/pwm_bl.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
On Wed, 08 Mar 2023, Uwe Kleine-König wrote: > The .remove() callback for a platform driver returns an int which makes > many driver authors wrongly assume it's possible to do error handling by > returning an error code. However the value returned is (mostly) ignored > and this typically results in resource leaks. To improve here there is a > quest to make the remove callback return void. In the first step of this > quest all drivers are converted to .remove_new() which already returns > void. > > Trivially convert this driver from always returning zero in the remove > callback to the void returning variant. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/video/backlight/qcom-wled.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
On Wed, 08 Mar 2023, Uwe Kleine-König wrote: > The .remove() callback for a platform driver returns an int which makes > many driver authors wrongly assume it's possible to do error handling by > returning an error code. However the value returned is (mostly) ignored > and this typically results in resource leaks. To improve here there is a > quest to make the remove callback return void. In the first step of this > quest all drivers are converted to .remove_new() which already returns > void. > > Trivially convert this driver from always returning zero in the remove > callback to the void returning variant. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/video/backlight/rt4831-backlight.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Applied, thanks -- Lee Jones [李琼斯]
Hello, this patch series adapts the platform drivers below drivers/video/backlight to use the .remove_new() callback. Compared to the traditional .remove() callback .remove_new() returns no value. This is a good thing because the driver core doesn't (and cannot) cope for errors during remove. The only effect of a non-zero return value in .remove() is that the driver core emits a warning. The device is removed anyhow and an early return from .remove() usually yields a resource leak. By changing the remove callback to return void driver authors cannot reasonably assume any more that there is some kind of cleanup later. All drivers in drivers/video/backlight returned zero unconditionally in their remove callback, so they could all be converted trivially to .remove_new(). Note that this series depends on commit 5c5a7680e67b ("platform: Provide a remove callback that returns no value") which is included in v6.3-rc1. Best regards Uwe Uwe Kleine-König (13): backlight: aat2870_bl: Convert to platform remove callback returning void backlight: adp5520_bl: Convert to platform remove callback returning void backlight: cr_bllcd: Convert to platform remove callback returning void backlight: da9052_bl: Convert to platform remove callback returning void backlight: hp680_bl: Convert to platform remove callback returning void backlight: led_bl: Convert to platform remove callback returning void backlight: lm3533_bl: Convert to platform remove callback returning void backlight: lp8788_bl: Convert to platform remove callback returning void backlight: mt6370-backlight: Convert to platform remove callback returning void backlight: pwm_bl: Convert to platform remove callback returning void backlight: qcom-wled: Convert to platform remove callback returning void backlight: rt4831-backlight: Convert to platform remove callback returning void backlight: sky81452-backlight: Convert to platform remove callback returning void drivers/video/backlight/aat2870_bl.c | 6 ++---- drivers/video/backlight/adp5520_bl.c | 6 ++---- drivers/video/backlight/cr_bllcd.c | 6 ++---- drivers/video/backlight/da9052_bl.c | 6 ++---- drivers/video/backlight/hp680_bl.c | 6 ++---- drivers/video/backlight/led_bl.c | 6 ++---- drivers/video/backlight/lm3533_bl.c | 6 ++---- drivers/video/backlight/lp8788_bl.c | 6 ++---- drivers/video/backlight/mt6370-backlight.c | 6 ++---- drivers/video/backlight/pwm_bl.c | 6 ++---- drivers/video/backlight/qcom-wled.c | 6 ++---- drivers/video/backlight/rt4831-backlight.c | 6 ++---- drivers/video/backlight/sky81452-backlight.c | 6 ++---- 13 files changed, 26 insertions(+), 52 deletions(-) base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6