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

[Chen-Yu Tsai]

Hi,

On Mon, Apr 12, 2021 at 8:08 AM Andre Przywara <andre.przywara at 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 at gmx.de>
> Reported-by: Daniel Kulesz <kuleszdl at posteo.org>
> Signed-off-by: Andre Przywara <andre.przywara at 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?
That way, at least on Linux, the mmc core resorts to polling for a card.
At least this way the card is still removable.


ChenYu