Re: [PATCH] arm64: dts: ti: k3-am62a7-sk: Disable mmc Schmitt Trigger

[Vitor Soares <ivitro@gmail.com>]

On Tue, 2026-01-06 at 17:22 +0100, Markus Schneider-Pargmann (TI.com) wrote:
> Remove Schmitt Trigger from mmc pins. With Schmitt Trigger enabled
> u-boot SPL is not able to read u-boot from mmc:
> 
>     Trying to boot from MMC2
>     Error reading cluster
>     spl_load_image_fat: error reading image u-boot.img, err - -22
>     Error: -22
>     SPL: Unsupported Boot Device!
>     SPL: failed to boot from all boot devices
>     ### ERROR ### Please RESET the board ###
> 
> I bisected this issue between u-boot v2025.10 and v2026.01 and found the
> devicetree merge to be the problem. At a closer look I found the
> k3-pinctrl.h changes. Disabling the Schmitt Trigger fixes the u-boot SPL
> failure to read from mmc.
> 
> Fixes: 5b272127884b ("arm64: dts: ti: k3-pinctrl: Enable Schmitt Trigger by
> default")
> Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp@baylibre.com>
> 
Hi Markus,

We're seeing a similar issue on Verdin AM62 with U-Boot 2026.01. The
board has complete SPL boot failure with no output at all.

This occurs in the same version you bisected (v2026.01 failing).
Could the Schmitt Trigger changes also affect Verdin AM62?

Best regards,
Vitor Soares