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

[Dmitry Baryshkov]

On Tue, Mar 17, 2026 at 11:12:35PM +0100, David Heidelberg via B4 Relay wrote:
> From: Petr Hodina <petr.hodina@xxxxxxxxxxxxxx>
> 
> 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@xxxxxxxxxxxxxxxx/

> 
> Signed-off-by: Petr Hodina <petr.hodina@xxxxxxxxxxxxxx>
> Signed-off-by: David Heidelberg <david@xxxxxxx>
> ---
>  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