Re: [PATCH 3/3] arm64: dts: qcom: sm7225-fairphone-fp4: Enable display and GPU

[Luca Weiss]

On Wed Jan 10, 2024 at 12:23 PM CET, Maxime Ripard wrote:
> On Wed, Jan 10, 2024 at 12:00:23PM +0100, Luca Weiss wrote:
> > On Wed Jan 10, 2024 at 11:58 AM CET, Konrad Dybcio wrote:
> > >
> > >
> > > On 1/5/24 15:29, Luca Weiss wrote:
> > > > Add the description for the display panel found on this phone and remove
> > > > the simple-framebuffer that was in place until now
> > >
> > > Why? They should be able to coexist with a smooth-ish handoff
> > 
> > Does that work upstream? I'm aware that downstream can do this but
> > thought this was still missing upstream.
>
> It depends what you call smooth-ish I guess, but KMS handles the
> handover just fine. You're likely to get a flicker during the transition
> though.

Right, seems to work. Also visually looks okay.

fairphone-fp4:~$ dmesg | grep "frame buffer device"
[    0.250511] Console: switching to colour frame buffer device 135x146
[    0.284146] simple-framebuffer a0000000.framebuffer: [drm] fb0: simpledrmdrmfb frame buffer device
[    2.576712] Console: switching to colour frame buffer device 135x146
[    2.604907] msm_dpu ae01000.display-controller: [drm] fb0: msmdrmfb frame buffer device

I thought before that having two outputs like this would cause two
different framebuffers/display devices to appear, but yeah as I said
seems okay. Will change in v2.

Regards
Luca

>
> Either way, the DT isn't the right place to choose, you should enable
> both, and the distro will choose its policy through configuration.
>
> Maxime