Re: [linux-sunxi] [PATCH] arm64: dts: allwinner: Revert SD card CD GPIO for Pine64-LTS

[Andre Przywara <andre.przywara@arm.com>]

On Mon, 12 Apr 2021 14:20:41 +0800
Chen-Yu Tsai <wens@csie.org> wrote:

> Hi,
> 
> On Mon, Apr 12, 2021 at 8:08 AM Andre Przywara <andre.przywara@arm.com> wrote:
> >
> > Commit 941432d00768 ("arm64: dts: allwinner: Drop non-removable from
> > SoPine/LTS SD card") enabled the card detect GPIO for the SOPine module,
> > along the way with the Pine64-LTS, which share the same base .dtsi.
> >
> > This was based on the observation that the Pine64-LTS has as "push-push"
> > SD card socket, and that the schematic mentions the card detect GPIO.
> >
> > After having received two reports about failing SD card access with that
> > patch, some more research and polls on that subject revealed that there
> > are at least two different versions of the Pine64-LTS out there:
> > - On some boards (including mine) the card detect pin is "stuck" at
> >   high, regardless of an microSD card being inserted or not.
> > - On other boards the card-detect is working, but is active-high, by
> >   virtue of an explicit inverter circuit, as shown in the schematic.
> >
> > To cover all versions of the board out there, and don't take any chances,
> > let's revert the introduction of the CD GPIO, and go back to the
> > non-removable property for the Pine64-LTS. That should avoid regressions
> > and should work for everyone.
> > The SOPine card detect has proven to be working, so let's keep that
> > GPIO in place.
> >
> > Fixes: 941432d00768 ("arm64: dts: allwinner: Drop non-removable from SoPine/LTS SD card")
> > Reported-by: Michael Weiser <michael.weiser@gmx.de>
> > Reported-by: Daniel Kulesz <kuleszdl@posteo.org>
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> >  arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts b/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts
> > index e79ce49e7e6a..843338e19694 100644
> > --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts
> > +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts
> > @@ -21,5 +21,5 @@
> >  };
> >
> >  &mmc0 {
> > -       cd-gpios = <&pio 5 6 GPIO_ACTIVE_LOW>; /* PF6 push-push switch */
> > +       non-removable;          /* card detect is broken on some boards */  
> 
> So a revert is good, but has anyone tried using the "broken-cd" instead?

Ha, that's a good idea, I totally forgot about this property!

> That way, at least on Linux, the mmc core resorts to polling for a card.
> At least this way the card is still removable.

Yes indeed, I tested it on my "stuck at 1" Pine64-LTS, and it works like
a charm!

Daniel, Michael, can you test this on your boards? So removing the
cd-gpios property, and adding "broken-cd;" instead?

Cheers,
Andre