Re: [PATCH] arm64: dts: allwinner: a523: x96qpro+: overvolting eMMC

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Bumping the eMMC IO regulator (`reg_cldo1`) to 1.9V inadvertently misconfigures the SoC's IO bank (Port C) into 3.3V power mode instead of 1.8V mode, creating a logic threshold mismatch.
--

--- Patch [1]: [PATCH] arm64: dts: allwinner: a523: x96qpro+: overvolting eMMC ---
commit e4c261c388d6e406babdf0d56ac61d104d537230
Author: Andre Przywara <[email protected]>
Date:   Mon Jul 20 21:38:32 2026 +0000

arm64: dts: allwinner: a523: x96qpro+: overvolting eMMC

This commit changes the eMMC IO regulator voltage on PortC from 1.8V to 1.9V
for the X96QPro+ device. The goal is to improve eMMC stability and performance
without drastically limiting the clock frequency.

> diff --git a/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts b/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts
> --- a/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts
> +++ b/arch/arm64/boot/dts/allwinner/sun55i-h728-x96qpro+.dts
[ ... ]
> @@ -194,8 +194,8 @@ reg_bldo4: bldo4 {
>  
>  			reg_cldo1: cldo1 {
>  				regulator-always-on;
> -				regulator-min-microvolt = <1800000>;
> -				regulator-max-microvolt = <1800000>;
> +				regulator-min-microvolt = <1900000>;
> +				regulator-max-microvolt = <1900000>;

[Severity: High]
Does bumping this regulator to 1.9V inadvertently force the SoC's IO bank
(Port C) into 3.3V power mode?

Looking at sunxi_pinctrl_set_io_bias_cfg() in
drivers/pinctrl/sunxi/pinctrl-sunxi.c, the driver uses a strict check when
evaluating the voltage:

    case BIAS_VOLTAGE_PIO_POW_MODE_SEL:
        val = uV <= 1800000 ? 1 : 0;

Since 1900000 is greater than 1800000, this evaluates to 0 and clears the
PIO_POW_MOD_SEL register bit, incorrectly configuring the IO bank for 3.3V
mode while being powered at 1.9V.

Could this mismatch alter input receiver thresholds and drive strengths,
potentially causing signal integrity issues or long-term hardware
degradation?

>  				regulator-name = "vcc-codec-sd";
>  			};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1