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From 91e8b74fe6381e083f8aa55217bb0562785ab398 Mon Sep 17 00:00:00 2001
From: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Date: Wed, 19 Oct 2022 16:27:27 +0200
Subject: [PATCH] arm64: dts: rockchip: lower rk3399-puma-haikou SD controller clock frequency
Git-commit: 91e8b74fe6381e083f8aa55217bb0562785ab398
Patch-mainline: v6.1-rc7
References: git-fixes

CRC errors (code -84 EILSEQ) have been observed for some SanDisk
Ultra A1 cards when running at 50MHz.

Waveform analysis suggest that the level shifters that are used on the
RK3399-Q7 module for voltage translation between 3.0 and 3.3V don't
handle clock rates at or above 48MHz properly. Back off to 40MHz for
some safety margin.

Cc: stable@vger.kernel.org
Fixes: 60fd9f72ce8a ("arm64: dts: rockchip: add Haikou baseboard with RK3399-Q7 SoM")
Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Link: https://lore.kernel.org/r/20221019-upstream-puma-sd-40mhz-v1-0-754a76421518@theobroma-systems.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts b/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts
index 04c752f49be9..115c14c0a3c6 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts
@@ -207,7 +207,7 @@ &sdmmc {
 	cap-sd-highspeed;
 	cd-gpios = <&gpio0 RK_PA7 GPIO_ACTIVE_LOW>;
 	disable-wp;
-	max-frequency = <150000000>;
+	max-frequency = <40000000>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&sdmmc_clk &sdmmc_cmd &sdmmc_cd &sdmmc_bus4>;
 	vmmc-supply = <&vcc3v3_baseboard>;
-- 
2.35.3