Re: [PATCH v2 5/5] arm64: dts: qcom: sdm845-xiaomi-beryllium-tianma: Disable MDSS

Dmitry Baryshkov
2026-04-12T00:37:02Z

On Fri, Apr 10, 2026 at 03:51:12PM +0200, David Heidelberg wrote:
> On 18/03/2026 15:47, Dmitry Baryshkov wrote:
> > On Tue, Mar 17, 2026 at 11:12:35PM +0100, David Heidelberg via B4 Relay wrote:
> > > From: Petr Hodina <petr.hodina@protonmail.com>
> > >
> > > Currently the panel driver for tianma is broken.
> > > Disable MDSS to prevent DRM taking over the framebuffer.
> >
> > I'd still hope that somebody can get it to work. I'd start by using
> > prepare_prev_first. Sumit reported the panel as working in 2020 and I
> > have no doubts that it was the case. Another option migt be something
> > related to the dispcc (see my [1]).
>
> Sadly, the prepare_prev_first didn't solve the issue. The framebuffer ->
> MDSS takover happens, but at greetd (login) loading screen goes black and
> never restores.
>
> Will need more work.

Do you see a console _while_ it boots, after the handover? I'd check the
mode programming. Maybe, disabling panel reset would also (temporarily)
help.

>
> David>
> > [1] https://lore.kernel.org/linux-arm-msm/20260217-sdm845-hdk-v1-1-866f1965fef7@oss.qualcomm.com/

--
With best wishes
Dmitry