[PATCH v2] arm64: dts: rockchip: Fix SD card init on rk3399-nanopi4

From: Christian Kohlschütter
Date: Thu Jul 14 2022 - 12:26:45 EST

mmc/SD-card initialization may fail on NanoPi r4s with
"mmc1: problem reading SD Status register" /
"mmc1: error -110 whilst initialising SD card"

Moreover, rebooting would also sometimes hang.

This is caused by the gpio entry for the vcc3v0-sd regulator;
even though it appears to be the correct GPIO pin, the presence
of the binding causes these errors.

Fix the regulator to drop the gpio binding and add a comment
to prevent accidental reintroduction of that entry.

Signed-off-by: Christian Kohlschütter <christian@xxxxxxxxxxxxxxxx>
arch/arm64/boot/dts/rockchip/rk3399-nanopi4.dtsi | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi4.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-nanopi4.dtsi
index 8c0ff6c96e03..d5f8a62e01be 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi4.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi4.dtsi
@@ -67,7 +67,7 @@ vcc1v8_s3: vcc1v8-s3 {
vcc3v0_sd: vcc3v0-sd {
compatible = "regulator-fixed";
- gpio = <&gpio0 RK_PA1 GPIO_ACTIVE_HIGH>;
+ // gpio = <&gpio0 RK_PA1 GPIO_ACTIVE_HIGH>; // breaks SDHC card support
pinctrl-names = "default";
pinctrl-0 = <&sdmmc0_pwr_h>;