From: David Bauer <mail@david-bauer.net>
Date: Tue, 25 Jan 2022 20:46:54 +0000 (+0100)
Subject: rockchip: disable UHS modes for NanoPi R4S
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=2b583ab8a74a6bd41f1c9629b3b66ba561d6fceb;p=openwrt%2Fstaging%2Fxback.git

rockchip: disable UHS modes for NanoPi R4S

The NanoPi R4S leaves the SD card in 1.8V signalling when rebooting
while U-Boot requires the card to be in 3.3V mode.

Remove UHS support from the SD controller so the card remains in 3.3V
mode. This reduces transfer speeds but ensures a reboot whether from
userspace or following a kernel panic is always working.

Signed-off-by: David Bauer <mail@david-bauer.net>
---

diff --git a/target/linux/rockchip/patches-5.10/105-nanopi-r4s-sd-signalling.patch b/target/linux/rockchip/patches-5.10/105-nanopi-r4s-sd-signalling.patch
new file mode 100644
index 0000000000..a04c14b70a
--- /dev/null
+++ b/target/linux/rockchip/patches-5.10/105-nanopi-r4s-sd-signalling.patch
@@ -0,0 +1,26 @@
+From: David Bauer <mail@david-bauer.net>
+Subject: arm64: dts: rockchip: disable UHS modes for NanoPi R4S
+
+The NanoPi R4S leaves the SD card in 1.8V signalling when rebooting
+while U-Boot requires the card to be in 3.3V mode.
+
+Remove UHS support from the SD controller so the card remains in 3.3V
+mode. This reduces transfer speeds but ensures a reboot whether from
+userspace or following a kernel panic is always working.
+
+Signed-off-by: David Bauer <mail@david-bauer.net>
+
+--- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
++++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
+@@ -121,6 +121,11 @@
+ 	status = "disabled";
+ };
+ 
++&sdmmc {
++	/delete-property/ sd-uhs-sdr104;
++	cap-sd-highspeed;
++};
++
+ &u2phy0_host {
+ 	phy-supply = <&vdd_5v>;
+ };