| Message ID | 20180425174253.4616-1-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wednesday, April 25, 2018 1:43 PM, Daniel Vetter wrote: > > The backlight power state handling is supremely confusing. We have: > - props.power, using FB_BLANK_* defines > - props.fb_blank, using the same, but deprecated int favour of > props.state > - props.state, using the BL_CORE_* defines > - and finally a bunch of backlight drivers treat brightness == 0 as > off. But of course not all of them. > > This is way too much confusion to fix in a simple patch, but at least > prevent more hilarity from spreading by removing the unused BL_CORE_* > defines. I have no idea why exactly anyone would need that. > > Wrt the ideal state, we really just want a boolean state. The 4 power > saving states that the fbdev subsystem uses are overkill in todays hw > (this was only relevant for VGA and similar analog circuits like > TV-out), the new drm atomic modeset api simplified even the uapi to a > simple bool. And there was never a valid technical reason to have the > intermediate fbdev power states for backlights (those really only can > be either off or on). > > Cleanup motivated by Meghana's questions about all this. > > Cc: Lee Jones <lee.jones@linaro.org> > Cc: Daniel Thompson <daniel.thompson@linaro.org> > Cc: Jingoo Han <jingoohan1@gmail.com> > Cc: Meghana Madhyastha <meghana.madhyastha@gmail.com> > Acked-by: Daniel Thompson <daniel.thompson@linaro.org> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: Jingoo Han <jingoohan1@gmail.com> I really love this patch! Good job! Thank you. Best regards, Jingoo Han > --- > include/linux/backlight.h | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index 2baab6f3861d..1db67662bfcb 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -84,9 +84,6 @@ struct backlight_properties { > > #define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */ > #define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb > blank event */ > -#define BL_CORE_DRIVER4 (1 << 28) /* reserved for driver > specific use */ > -#define BL_CORE_DRIVER3 (1 << 29) /* reserved for driver > specific use */ > -#define BL_CORE_DRIVER2 (1 << 30) /* reserved for driver > specific use */ > #define BL_CORE_DRIVER1 (1 << 31) /* reserved for driver > specific use */ > > }; > -- > 2.17.0
On Wed, 25 Apr 2018, Daniel Vetter <daniel.vetter@ffwll.ch> wrote: > The backlight power state handling is supremely confusing. We have: > - props.power, using FB_BLANK_* defines > - props.fb_blank, using the same, but deprecated int favour of > props.state > - props.state, using the BL_CORE_* defines > - and finally a bunch of backlight drivers treat brightness == 0 as > off. But of course not all of them. > > This is way too much confusion to fix in a simple patch, but at least > prevent more hilarity from spreading by removing the unused BL_CORE_* > defines. I have no idea why exactly anyone would need that. > > Wrt the ideal state, we really just want a boolean state. The 4 power > saving states that the fbdev subsystem uses are overkill in todays hw > (this was only relevant for VGA and similar analog circuits like > TV-out), the new drm atomic modeset api simplified even the uapi to a > simple bool. And there was never a valid technical reason to have the > intermediate fbdev power states for backlights (those really only can > be either off or on). > > Cleanup motivated by Meghana's questions about all this. > > Cc: Lee Jones <lee.jones@linaro.org> > Cc: Daniel Thompson <daniel.thompson@linaro.org> > Cc: Jingoo Han <jingoohan1@gmail.com> > Cc: Meghana Madhyastha <meghana.madhyastha@gmail.com> > Acked-by: Daniel Thompson <daniel.thompson@linaro.org> > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> > --- > include/linux/backlight.h | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/include/linux/backlight.h b/include/linux/backlight.h > index 2baab6f3861d..1db67662bfcb 100644 > --- a/include/linux/backlight.h > +++ b/include/linux/backlight.h > @@ -84,9 +84,6 @@ struct backlight_properties { > > #define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */ > #define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */ > -#define BL_CORE_DRIVER4 (1 << 28) /* reserved for driver specific use */ > -#define BL_CORE_DRIVER3 (1 << 29) /* reserved for driver specific use */ > -#define BL_CORE_DRIVER2 (1 << 30) /* reserved for driver specific use */ > #define BL_CORE_DRIVER1 (1 << 31) /* reserved for driver specific use */ > > };
On Wed, 25 Apr 2018, Daniel Vetter wrote: > The backlight power state handling is supremely confusing. We have: > - props.power, using FB_BLANK_* defines > - props.fb_blank, using the same, but deprecated int favour of > props.state > - props.state, using the BL_CORE_* defines > - and finally a bunch of backlight drivers treat brightness == 0 as > off. But of course not all of them. > > This is way too much confusion to fix in a simple patch, but at least > prevent more hilarity from spreading by removing the unused BL_CORE_* > defines. I have no idea why exactly anyone would need that. > > Wrt the ideal state, we really just want a boolean state. The 4 power > saving states that the fbdev subsystem uses are overkill in todays hw > (this was only relevant for VGA and similar analog circuits like > TV-out), the new drm atomic modeset api simplified even the uapi to a > simple bool. And there was never a valid technical reason to have the > intermediate fbdev power states for backlights (those really only can > be either off or on). > > Cleanup motivated by Meghana's questions about all this. All applied, thanks.
diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 2baab6f3861d..1db67662bfcb 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -84,9 +84,6 @@ struct backlight_properties { #define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */ #define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */ -#define BL_CORE_DRIVER4 (1 << 28) /* reserved for driver specific use */ -#define BL_CORE_DRIVER3 (1 << 29) /* reserved for driver specific use */ -#define BL_CORE_DRIVER2 (1 << 30) /* reserved for driver specific use */ #define BL_CORE_DRIVER1 (1 << 31) /* reserved for driver specific use */ };