Re: [PATCH] ARM: dts: stm32: Drop bias-disable from STM32MP15xx DHCOM SoM sdmmc1_b4_pins_a

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Missing bias overrides for 'opendrain' and 'init' pinctrl states.
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commit 9ff09c9ba4ada67d4ecaab0a65874ab8bca8e136
Author: Marek Vasut <marex@nabladev.com>
Subject: ARM: dts: stm32: Drop bias-disable from STM32MP15xx DHCOM SoM sdmmc1_b4_pins_a

This patch drops the bias-disable property from sdmmc1_b4_pins_a in the 
STM32MP15xx DHCOM SoM device tree to fix a DT checker warning. It ensures 
bias-pull-up is the only bias-related property present in the pinctrl 
subnodes for this state.

> diff --git a/arch/arm/boot/dts/st/stm32mp15xx-dhcom-som.dtsi b/arch/arm/boot/dts/st/stm32mp15xx-dhcom-som.dtsi
> index 4cc633683c6b7..0a4263e6209d8 100644
> --- a/arch/arm/boot/dts/st/stm32mp15xx-dhcom-som.dtsi
> +++ b/arch/arm/boot/dts/st/stm32mp15xx-dhcom-som.dtsi
> @@ -505,9 +505,11 @@ &sdmmc1_b4_pins_a {
>  	 * - mandatory on SoMs without SD voltage translator
>  	 */
>  	pins1 {
> +		/delete-property/ bias-disable;
>  		bias-pull-up;
>  	};
>  	pins2 {
> +		/delete-property/ bias-disable;
>  		bias-pull-up;
>  	};
>  };

[Severity: High]
This isn't a bug introduced by this patch, but should the bias properties 
also be overridden for the opendrain and init pinctrl states?

Earlier in arch/arm/boot/dts/st/stm32mp15xx-dhcom-som.dtsi, the sdmmc1 
node defines these additional states:

&sdmmc1 {
	pinctrl-names = "default", "opendrain", "sleep", "init";
	pinctrl-0 = <&sdmmc1_b4_pins_a &sdmmc1_dir_pins_a>;
	pinctrl-1 = <&sdmmc1_b4_od_pins_a &sdmmc1_dir_pins_a>;
	pinctrl-2 = <&sdmmc1_b4_sleep_pins_a &sdmmc1_dir_sleep_pins_a>;
	pinctrl-3 = <&sdmmc1_b4_init_pins_a &sdmmc1_dir_init_pins_a>;
...
};

Without similar overrides for &sdmmc1_b4_od_pins_a and 
&sdmmc1_b4_init_pins_a, they will inherit bias-disable from the base 
dtsi (stm32mp15-pinctrl.dtsi) when the MMC core automatically selects 
the opendrain or init states during card initialization and specific modes.

Since internal pull-ups are mandatory on SoMs without an SD voltage 
translator, couldn't inheriting bias-disable leave the bus lines floating 
during card initialization and cause storage failures?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260828150111.173089-1-marex@nabladev.com?part=1