| Message ID | 1396087871-9091-1-git-send-email-shc_work@mail.ru (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> Use the SIMPLE_DEV_PM_OPS() macro to declare the driver's pm_ops. > > Signed-off-by: Alexander Shiyan <shc_work@mail.ru> > --- > drivers/video/backlight/pwm_bl.c | 17 ++++------------- > 1 file changed, 4 insertions(+), 13 deletions(-) > > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > index b75201f..d5e1f5b 100644 > --- a/drivers/video/backlight/pwm_bl.c > +++ b/drivers/video/backlight/pwm_bl.c [...] > -static int pwm_backlight_resume(struct device *dev) > +static int __maybe_unused pwm_bl_resume(struct device *dev) What's the __maybe_unused attribute for? In include/linux/compiler-gcc.h it redefines the attribute as 'unused': #define __maybe_unused __attribute__((unused)) ... are you sure this is what you want?
> > > Use the SIMPLE_DEV_PM_OPS() macro to declare the driver's pm_ops. > > > > > > Signed-off-by: Alexander Shiyan <shc_work@mail.ru> > > > --- > > > drivers/video/backlight/pwm_bl.c | 17 ++++------------- > > > 1 file changed, 4 insertions(+), 13 deletions(-) > > > > > > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > > > index b75201f..d5e1f5b 100644 > > > --- a/drivers/video/backlight/pwm_bl.c > > > +++ b/drivers/video/backlight/pwm_bl.c > > > > [...] > > > > > -static int pwm_backlight_resume(struct device *dev) > > > +static int __maybe_unused pwm_bl_resume(struct device *dev) > > > > What's the __maybe_unused attribute for? > > > > In include/linux/compiler-gcc.h it redefines the attribute as 'unused': > > > > #define __maybe_unused __attribute__((unused)) > > > > ... are you sure this is what you want? > > Yes. This avoids compiler warnings if CONFIG_PM is unset. What are the advantages of this over the config option? Besides 2 lines of code?
> > > > > Use the SIMPLE_DEV_PM_OPS() macro to declare the driver's pm_ops. > > > > > > > > > > Signed-off-by: Alexander Shiyan <shc_work@mail.ru> > > > > > --- > > > > > drivers/video/backlight/pwm_bl.c | 17 ++++------------- > > > > > 1 file changed, 4 insertions(+), 13 deletions(-) > > > > > > > > > > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > > > > > index b75201f..d5e1f5b 100644 > > > > > --- a/drivers/video/backlight/pwm_bl.c > > > > > +++ b/drivers/video/backlight/pwm_bl.c > > > > > > > > [...] > > > > > > > > > -static int pwm_backlight_resume(struct device *dev) > > > > > +static int __maybe_unused pwm_bl_resume(struct device *dev) > > > > > > > > What's the __maybe_unused attribute for? > > > > > > > > In include/linux/compiler-gcc.h it redefines the attribute as 'unused': > > > > > > > > #define __maybe_unused __attribute__((unused)) > > > > > > > > ... are you sure this is what you want? > > > > > > Yes. This avoids compiler warnings if CONFIG_PM is unset. > > > > What are the advantages of this over the config option? Besides 2 > > lines of code? > > Just an increase compile coverage. What does this mean? I replied to another one of your patches with the same question.
Mon, 31 Mar 2014 09:50:47 +0100 ?? Lee Jones <lee.jones@linaro.org>: > > > > > > Use the SIMPLE_DEV_PM_OPS() macro to declare the driver's pm_ops. > > > > > > > > > > > > Signed-off-by: Alexander Shiyan <shc_work@mail.ru> > > > > > > --- > > > > > > drivers/video/backlight/pwm_bl.c | 17 ++++------------- > > > > > > 1 file changed, 4 insertions(+), 13 deletions(-) > > > > > > > > > > > > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > > > > > > index b75201f..d5e1f5b 100644 > > > > > > --- a/drivers/video/backlight/pwm_bl.c > > > > > > +++ b/drivers/video/backlight/pwm_bl.c > > > > > > > > > > [...] > > > > > > > > > > > -static int pwm_backlight_resume(struct device *dev) > > > > > > +static int __maybe_unused pwm_bl_resume(struct device *dev) > > > > > > > > > > What's the __maybe_unused attribute for? > > > > > > > > > > In include/linux/compiler-gcc.h it redefines the attribute as 'unused': > > > > > > > > > > #define __maybe_unused __attribute__((unused)) > > > > > > > > > > ... are you sure this is what you want? > > > > > > > > Yes. This avoids compiler warnings if CONFIG_PM is unset. > > > > > > What are the advantages of this over the config option? Besides 2 > > > lines of code? > > > > Just an increase compile coverage. > > What does this mean? I replied to another one of your patches with the > same question. Code parts for suspend() and resume() will be compiled regardless of CONFIG_PM option and will be discarded by linker if CONFIG_PM is not set. ---
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index b75201f..d5e1f5b 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c @@ -359,8 +359,7 @@ static int pwm_backlight_remove(struct platform_device *pdev) return 0; } -#ifdef CONFIG_PM_SLEEP -static int pwm_backlight_suspend(struct device *dev) +static int __maybe_unused pwm_bl_suspend(struct device *dev) { struct backlight_device *bl = dev_get_drvdata(dev); struct pwm_bl_data *pb = bl_get_data(bl); @@ -376,7 +375,7 @@ static int pwm_backlight_suspend(struct device *dev) return 0; } -static int pwm_backlight_resume(struct device *dev) +static int __maybe_unused pwm_bl_resume(struct device *dev) { struct backlight_device *bl = dev_get_drvdata(dev); @@ -384,22 +383,14 @@ static int pwm_backlight_resume(struct device *dev) return 0; } -#endif -static const struct dev_pm_ops pwm_backlight_pm_ops = { -#ifdef CONFIG_PM_SLEEP - .suspend = pwm_backlight_suspend, - .resume = pwm_backlight_resume, - .poweroff = pwm_backlight_suspend, - .restore = pwm_backlight_resume, -#endif -}; +static SIMPLE_DEV_PM_OPS(pwm_bl_pm_ops, pwm_bl_suspend, pwm_bl_resume); static struct platform_driver pwm_backlight_driver = { .driver = { .name = "pwm-backlight", .owner = THIS_MODULE, - .pm = &pwm_backlight_pm_ops, + .pm = &pwm_bl_pm_ops, .of_match_table = of_match_ptr(pwm_backlight_of_match), }, .probe = pwm_backlight_probe,
Use the SIMPLE_DEV_PM_OPS() macro to declare the driver's pm_ops. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> --- drivers/video/backlight/pwm_bl.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-)