[PATCH] arm64: dts: amlogic: sm1-bananapi: lower SD card speed for stability

[Martin Blumenstingl]

On Mon, May 5, 2025 at 4:37 PM Christian Hewitt
<christianshewitt at gmail.com> wrote:
>
> Users report being able to boot (u-boot) from SD card but kernel
> init then fails to mount partitions on the card containing boot
> media resulting in first-boot failure. System logs show only the
> probe of the mmc devices: the SD card is seen, but no partitions
> are found so init fails to mount them and boot stalls.
>
> Reducing the speed of the SD card from 50MHz to 35MHz results in
> complete probing of the card and successful boot.
>
> Signed-off-by: Christian Hewitt <christianshewitt at gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>

> ---
> The same workaround of dropping to 35MHz is also done with the
> ac2xx dtsi; which has a comment about CRC errors being seen at
> 50MHz. It's probable this is the same although I forget now how
> that diagnosis was done (or who did it, Martin perhaps?).
Maybe Jerome helped investigate/debug? I can't recall and at the same
time: if it fixes the end user experience it's a win.