| Message ID | 20201013010056.v2.2.I96b8d872ec51171f19274e43e96cadc092881271@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | PWM backlight interpolation adjustments | expand |
On Tue, Oct 13, 2020 at 01:01:02AM -0700, Alexandru Stan wrote: > After the "PWM backlight interpolation adjustments" patches, the > backlight interpolation works a little differently. The way these > dts files were working before was relying on a bug (IMHO). > > Remove the 0-3 range since otherwise we would have a 252 long > interpolation that would slowly go between 0 and 3, looking really bad > in userspace. > > We don't need the 0% point, userspace seems to handle this just fine > because it uses the bl_power property to turn off the display. > > Signed-off-by: Alexandru Stan <amstan@chromium.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Note also shouldn't this be patch 1 of the set. AFAICT it makes sense whether or not the interpolation algorithm is changed. Daniel. > --- > > arch/arm/boot/dts/rk3288-veyron-jaq.dts | 2 +- > arch/arm/boot/dts/rk3288-veyron-minnie.dts | 2 +- > arch/arm/boot/dts/rk3288-veyron-tiger.dts | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/boot/dts/rk3288-veyron-jaq.dts b/arch/arm/boot/dts/rk3288-veyron-jaq.dts > index af77ab20586d..4a148cf1defc 100644 > --- a/arch/arm/boot/dts/rk3288-veyron-jaq.dts > +++ b/arch/arm/boot/dts/rk3288-veyron-jaq.dts > @@ -20,7 +20,7 @@ / { > > &backlight { > /* Jaq panel PWM must be >= 3%, so start non-zero brightness at 8 */ > - brightness-levels = <0 8 255>; > + brightness-levels = <8 255>; > num-interpolated-steps = <247>; > }; > > diff --git a/arch/arm/boot/dts/rk3288-veyron-minnie.dts b/arch/arm/boot/dts/rk3288-veyron-minnie.dts > index f8b69e0a16a0..82fc6fba9999 100644 > --- a/arch/arm/boot/dts/rk3288-veyron-minnie.dts > +++ b/arch/arm/boot/dts/rk3288-veyron-minnie.dts > @@ -39,7 +39,7 @@ volum_up { > > &backlight { > /* Minnie panel PWM must be >= 1%, so start non-zero brightness at 3 */ > - brightness-levels = <0 3 255>; > + brightness-levels = <3 255>; > num-interpolated-steps = <252>; > }; > > diff --git a/arch/arm/boot/dts/rk3288-veyron-tiger.dts b/arch/arm/boot/dts/rk3288-veyron-tiger.dts > index 069f0c2c1fdf..52a84cbe7a90 100644 > --- a/arch/arm/boot/dts/rk3288-veyron-tiger.dts > +++ b/arch/arm/boot/dts/rk3288-veyron-tiger.dts > @@ -23,7 +23,7 @@ / { > > &backlight { > /* Tiger panel PWM must be >= 1%, so start non-zero brightness at 3 */ > - brightness-levels = <0 3 255>; > + brightness-levels = <3 255>; > num-interpolated-steps = <252>; > }; > > -- > 2.28.0 >
On Wed, Oct 14, 2020 at 7:19 AM Daniel Thompson <daniel.thompson@linaro.org> wrote: > > On Tue, Oct 13, 2020 at 01:01:02AM -0700, Alexandru Stan wrote: > > After the "PWM backlight interpolation adjustments" patches, the > > backlight interpolation works a little differently. The way these > > dts files were working before was relying on a bug (IMHO). > > > > Remove the 0-3 range since otherwise we would have a 252 long > > interpolation that would slowly go between 0 and 3, looking really bad > > in userspace. > > > > We don't need the 0% point, userspace seems to handle this just fine > > because it uses the bl_power property to turn off the display. > > > > Signed-off-by: Alexandru Stan <amstan@chromium.org> > > Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Thank you! > > Note also shouldn't this be patch 1 of the set. AFAICT it makes sense > whether or not the interpolation algorithm is changed. Yeah, I guess it could be. Sorry I didn't think of it that way before, I'm used to landing things in a group. In particular on veyron I assume it will almost be a noop without having my driver patch (especially with the findings of 0% not being that important). Feel free to land this independently. > > > Daniel. Alexandru Stan (amstan)
diff --git a/arch/arm/boot/dts/rk3288-veyron-jaq.dts b/arch/arm/boot/dts/rk3288-veyron-jaq.dts index af77ab20586d..4a148cf1defc 100644 --- a/arch/arm/boot/dts/rk3288-veyron-jaq.dts +++ b/arch/arm/boot/dts/rk3288-veyron-jaq.dts @@ -20,7 +20,7 @@ / { &backlight { /* Jaq panel PWM must be >= 3%, so start non-zero brightness at 8 */ - brightness-levels = <0 8 255>; + brightness-levels = <8 255>; num-interpolated-steps = <247>; }; diff --git a/arch/arm/boot/dts/rk3288-veyron-minnie.dts b/arch/arm/boot/dts/rk3288-veyron-minnie.dts index f8b69e0a16a0..82fc6fba9999 100644 --- a/arch/arm/boot/dts/rk3288-veyron-minnie.dts +++ b/arch/arm/boot/dts/rk3288-veyron-minnie.dts @@ -39,7 +39,7 @@ volum_up { &backlight { /* Minnie panel PWM must be >= 1%, so start non-zero brightness at 3 */ - brightness-levels = <0 3 255>; + brightness-levels = <3 255>; num-interpolated-steps = <252>; }; diff --git a/arch/arm/boot/dts/rk3288-veyron-tiger.dts b/arch/arm/boot/dts/rk3288-veyron-tiger.dts index 069f0c2c1fdf..52a84cbe7a90 100644 --- a/arch/arm/boot/dts/rk3288-veyron-tiger.dts +++ b/arch/arm/boot/dts/rk3288-veyron-tiger.dts @@ -23,7 +23,7 @@ / { &backlight { /* Tiger panel PWM must be >= 1%, so start non-zero brightness at 3 */ - brightness-levels = <0 3 255>; + brightness-levels = <3 255>; num-interpolated-steps = <252>; };
After the "PWM backlight interpolation adjustments" patches, the backlight interpolation works a little differently. The way these dts files were working before was relying on a bug (IMHO). Remove the 0-3 range since otherwise we would have a 252 long interpolation that would slowly go between 0 and 3, looking really bad in userspace. We don't need the 0% point, userspace seems to handle this just fine because it uses the bl_power property to turn off the display. Signed-off-by: Alexandru Stan <amstan@chromium.org> --- arch/arm/boot/dts/rk3288-veyron-jaq.dts | 2 +- arch/arm/boot/dts/rk3288-veyron-minnie.dts | 2 +- arch/arm/boot/dts/rk3288-veyron-tiger.dts | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-)