Re: [PATCH] mmc: dts: am654: Add 650ms power off delay for proper MMC power cycle

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `power-off-delay-us` property is added directly to the MMC host controller node, where it is completely ignored, rendering the boot failure fix entirely ineffective.
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commit 02105a5fc6c6d24da9df99e671b001a1f3cd6d1c
Author: Judith Mendez <jm@ti.com>

mmc: dts: am654: Add 650ms power off delay for proper MMC power cycle

This commit attempts to fix a boot failure caused by incomplete VDD
discharge during MMC power cycles. It adds a power-off-delay-us property
to the sdhci1 node to provide time for the RC circuit to discharge.

> diff --git a/arch/arm64/boot/dts/ti/k3-am654-base-board.dts b/arch/arm64/boot/dts/ti/k3-am654-base-board.dts
> --- a/arch/arm64/boot/dts/ti/k3-am654-base-board.dts
> +++ b/arch/arm64/boot/dts/ti/k3-am654-base-board.dts
> @@ -460,6 +460,7 @@ &sdhci0 {
>  &sdhci1 {
>  	status = "okay";
>  	vmmc-supply = <&vdd_mmc1_sd>;
> +	power-off-delay-us = <650000>;

[Severity: Medium]
Will this property actually be parsed by the MMC core here?

When placed directly in the MMC host controller node, the power-off-delay-us
property is completely ignored. It is only parsed when placed inside an
mmc-pwrseq-simple node, rendering this proposed fix ineffective.

Furthermore, even if it were parsed via a pwrseq node, the
mmc_pwrseq_power_off() delay executes before the VDD regulator is disabled by
mmc_set_ios(). This means the delay would occur while VDD is still actively
driven, failing to provide the required time for the RC circuit to discharge.

Should this instead be implemented by adding an off-on-delay-us property
directly to the vdd_mmc1_sd regulator node?

>  	pinctrl-names = "default";
>  	pinctrl-0 = <&main_mmc1_pins_default>;
>  	ti,driver-strength-ohm = <50>;

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Sashiko AI review · https://sashiko.dev/#/patchset/20260908170635.238775-1-jm@ti.com?part=1