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

[Da Xue]

On Tue, May 6, 2025 at 2:26 AM Martin Blumenstingl
<martin.blumenstingl at googlemail.com> wrote:
>
> 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.

We had an issue too and ended up disabling MMC_MODE_HS_52MHz | MMC_MODE_HS;

>
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