Re: [PATCH v2 3/3] arm64: dts: qcom: trogdor: Add brightness-levels

From: Daniel Thompson
Date: Wed Oct 14 2020 - 07:33:21 EST


On Tue, Oct 13, 2020 at 09:28:38AM -0700, Doug Anderson wrote:
> Hi,
>
> On Tue, Oct 13, 2020 at 1:01 AM Alexandru Stan <amstan@xxxxxxxxxxxx> wrote:
> >
> > Now that we have better interpolation for the backlight
> > ("backlight: pwm_bl: Fix interpolation"), we can now add the curve to
> > the trogdor boards, being careful to crop the low end.
>
> Just to make it clear, the patch this depends on hasn't landed yet.
> Presumably it will land in the v5.10 timeframe? That means that
> without extra coordination this patch can target v5.11.

You're talking about patch 1 from this set? Despite the title I view
the patch as changing policy (albeit one that does also fix some annoying
quantization errors at the same time) so it's not necessarily a
candidate for merging outside the merge window (I've not checked with
Lee but I think it likely the shutter is already down for features).

Moreover I'm not clear why there a dependency here that would stop the
changes landing in different trees.


Daniel.


> > Signed-off-by: Alexandru Stan <amstan@xxxxxxxxxxxx>
> > ---
> >
> > arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 9 +++++++++
> > 1 file changed, 9 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
> > index bf875589d364..ccdabc6c4994 100644
> > --- a/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
> > @@ -179,6 +179,15 @@ pp3300_fp_tp: pp3300-fp-tp-regulator {
> > backlight: backlight {
> > compatible = "pwm-backlight";
> >
> > + /* The panels don't seem to like anything below ~ 5% */
> > + brightness-levels = <
> > + 196 256 324 400 484 576 676 784 900 1024 1156 1296
> > + 1444 1600 1764 1936 2116 2304 2500 2704 2916 3136
> > + 3364 3600 3844 4096
> > + >;
> > + num-interpolated-steps = <64>;
> > + default-brightness-level = <951>;
>
> I haven't done lots of digging here, but this matches what Alexandru
> and Matthias agreed upon for the downstream tree and seems sane.
> Thus:
>
> Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>