From: Jakob Unterwurzacher jakob.unterwurzacher@theobroma-systems.com
commit 91e8b74fe6381e083f8aa55217bb0562785ab398 upstream.
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@... Signed-off-by: Heiko Stuebner heiko@sntech.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts +++ b/arch/arm64/boot/dts/rockchip/rk3399-puma-haikou.dts @@ -180,7 +180,7 @@ 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>;