Re: [PATCH v2] arm64: dts: qcom: sm8250-edo: Panel framebuffer is 2.5k instead of 4k

[AngeloGioacchino Del Regno]

Il 14/06/23 14:43, Konrad Dybcio ha scritto:
> On 14.06.2023 14:40, Marijn Suijten wrote:
> > On 2023-06-07 09:15:08, AngeloGioacchino Del Regno wrote:
> > > Il 07/06/23 00:52, Konrad Dybcio ha scritto:
> > > > On 6.06.2023 23:14, Marijn Suijten wrote:
> > > > > The framebuffer configuration for edo pdx203, written in edo dtsi (which
> > > > > is overwritten in pdx206 dts for its smaller panel) has to use a
> > > > > 1096x2560 configuration as this is what the panel (and framebuffer area)
> > > > > has been initialized to.  Downstream userspace also has access to (and
> > > > > uses) this 2.5k mode by default, and only switches the panel to 4k when
> > > > > requested.
> > > > >
> > > > > This is similar to commit be8de06dc397 ("arm64: dts: qcom:
> > > > > sm8150-kumano: Panel framebuffer is 2.5k instead of 4k") which fixed the
> > > > > same for the previous generation Sony platform.
> > > > >
> > > > > Fixes: 69cdb97ef652 ("arm64: dts: qcom: sm8250: Add support for SONY Xperia 1 II / 5 II (Edo platform)")
> > > > > Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> > > > > ---
> > > > And so I derped again.
> > > >
> > > > Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> > >
> > > I would've liked more to see a commit saying "replace simple-framebuffer with xxxx"
> > > (where xxxx is DSI panel, etc) but that will as well do for now... :-)
> >
> > Fwiw we could keep it around as MDSS "gracefully" takes over when it
> > probes a little bit later with fbcon over DRM/KMS, and it sometimes
> > helps reading what is up when something fails before or during MDSS
> > probe.
> I believe we should do this. Perhaps even add some early code to drm/msm
> that'd read out the address (and other configuration) from the mdp hw and
> set it up automagically.

As far as I remember, some bootloaders are reading devicetrees to setup the display
at boot with "continuous splash", that's why I would be for *replacing* the simple
framebuffer with the mdss-dsi.

Adding early code to drm/msm to read out the address and check the state of the HW
before pushing an early framebuffer would be a definitive solution for that corner
case. Good call, Konrad.

Cheers,
Angelo

> Konrad
> > - Marijn
> >
> > > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> > >
> > > > Konrad
> > > > > Changes since v2:
> > > > > - Rename griffin (copy-paste from related patch) to pdx203 in comment.
> > > > >
> > > > >    arch/arm64/boot/dts/qcom/sm8250-sony-xperia-edo.dtsi | 7 ++++---
> > > > >    1 file changed, 4 insertions(+), 3 deletions(-)
> > > > >
> > > > > diff --git a/arch/arm64/boot/dts/qcom/sm8250-sony-xperia-edo.dtsi b/arch/arm64/boot/dts/qcom/sm8250-sony-xperia-edo.dtsi
> > > > > index 3d22be747f042..8f867f841cb83 100644
> > > > > --- a/arch/arm64/boot/dts/qcom/sm8250-sony-xperia-edo.dtsi
> > > > > +++ b/arch/arm64/boot/dts/qcom/sm8250-sony-xperia-edo.dtsi
> > > > > @@ -54,9 +54,10 @@ chosen {
> > > > >    		framebuffer: framebuffer@9c000000 {
> > > > >    			compatible = "simple-framebuffer";
> > > > >    			reg = <0 0x9c000000 0 0x2300000>;
> > > > > -			width = <1644>;
> > > > > -			height = <3840>;
> > > > > -			stride = <(1644 * 4)>;
> > > > > +			/* pdx203 BL initializes in 2.5k mode, not 4k */
> > > > > +			width = <1096>;
> > > > > +			height = <2560>;
> > > > > +			stride = <(1096 * 4)>;
> > > > >    			format = "a8r8g8b8";
> > > > >    		};
> > > > >    	};