Re: [PATCH 7/8] arm64: dts: ti: k3-am64-sk: Disable MMC1 internal pulls

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Unintended removal of pulldown and incorrect receiver state for `MMC1_CLK`.
--

--- Patch [7]: [PATCH 7/8] arm64: dts: ti: k3-am64-sk: Disable MMC1 internal pulls ---
commit 3a83d1bd44a1ef684b5bd29a93a2127e82509201
Author: Judith Mendez <jm@ti.com>

arm64: dts: ti: k3-am64-sk: Disable MMC1 internal pulls

This commit drops internal pullups on MMC data and CMD pins to prevent violating
minimum pull resistance specifications, as external pullups are already present
on the board. It also removes the CD pullup to reduce power consumption.

> diff --git a/arch/arm64/boot/dts/ti/k3-am642-sk.dts b/arch/arm64/boot/dts/ti/k3-am642-sk.dts
> --- a/arch/arm64/boot/dts/ti/k3-am642-sk.dts
> +++ b/arch/arm64/boot/dts/ti/k3-am642-sk.dts
> @@ -198,13 +198,13 @@ &main_pmx0 {
>  	main_mmc1_pins_default: main-mmc1-default-pins {
>  		bootph-all;
>  		pinctrl-single,pins = <
> -			AM64X_IOPAD(0x0298, PIN_INPUT_PULLUP, 0) /* (D19) MMC1_SDCD */
> -			AM64X_IOPAD(0x0294, PIN_INPUT_PULLUP, 0) /* (J19) MMC1_CMD */
> -			AM64X_IOPAD(0x028c, PIN_INPUT_PULLDOWN, 0) /* (L20) MMC1_CLK */
> +			AM64X_IOPAD(0x0298, PIN_INPUT, 0) /* (D19) MMC1_SDCD */
> +			AM64X_IOPAD(0x0294, PIN_INPUT, 0) /* (J19) MMC1_CMD */
> +			AM64X_IOPAD(0x028c, PIN_INPUT, 0) /* (L20) MMC1_CLK */

[Severity: Medium]
The commit message mentions removing internal pullups because of external
pullups on the board, but MMC1_CLK in main_mmc1_pins_default was configured
with PIN_INPUT_PULLDOWN. Does this blanket change unintentionally leave the clock
pin floating when the MMC controller tri-states the clock line (for example,
during idle or suspend)?

Additionally, keeping this as PIN_INPUT leaves the receiver enabled. If the
clock line floats without a pulldown, could the floating voltage cause the input
receiver to rapidly toggle and increase power consumption? Should this pin be
configured as OUTPUT-only instead?

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260729195958.671147-1-jm@ti.com?part=7