[PATCH 4/7] arm64: dts: imx8mm-venice-gw7902: Increase HS400 USDHC clock speed

Tim Harvey tharvey at gateworks.com
Mon Jul 7 13:16:59 PDT 2025


The IMX8M reference manuals indicate in the USDHC Clock generator section
that the clock rate for DDR is 1/2 the input clock therefore HS400 rates
clocked at 200Mhz require a 400Mhz SDHC clock.

This showed about a 1.5x improvement in read performance for the eMMC's
used on the various imx8m{m,n,p}-venice boards.

Fixes: ef484dfcf6f7 ("arm64: dts: imx: Add i.mx8mm/imx8mn Gateworks gw7902 dts support")
Signed-off-by: Tim Harvey <tharvey at gateworks.com>
---
 arch/arm64/boot/dts/freescale/imx8mm-venice-gw7902.dts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7902.dts b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7902.dts
index 46d1ee0a4ee8..c09b40fc6dec 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7902.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw7902.dts
@@ -743,6 +743,8 @@ &usdhc3 {
 	pinctrl-0 = <&pinctrl_usdhc3>;
 	pinctrl-1 = <&pinctrl_usdhc3_100mhz>;
 	pinctrl-2 = <&pinctrl_usdhc3_200mhz>;
+	assigned-clocks = <&clk IMX8MM_CLK_USDHC3>;
+	assigned-clock-rates = <400000000>;
 	bus-width = <8>;
 	non-removable;
 	status = "okay";
-- 
2.25.1




More information about the linux-arm-kernel mailing list