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

Dmitry Baryshkov
2026-03-18T14:47:32Z

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]).

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

>
> Signed-off-by: Petr Hodina <petr.hodina@protonmail.com>
> Signed-off-by: David Heidelberg <david@ixit.cz>
> ---
> arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts b/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts
> index b58964cde8342..d1c7bccaab500 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-xiaomi-beryllium-tianma.dts
> @@ -36,3 +36,13 @@ touchscreen@1 {
> touchscreen-size-y = <2246>;
> };
> };
> +
> +&dispcc {
> + /* Disable for now so simple-framebuffer continues working */
> + status = "disabled";
> +};
> +
> +&mdss {
> + /* Disable for now so simple-framebuffer continues working */
> + status = "disabled";
> +};
>
> --
> 2.53.0
>
>

--
With best wishes
Dmitry