[PATCH 1/7] arm64: dts: imx8mm-venice-gw700x: Increase HS400 USDHC clock speed

Tim Harvey tharvey at gateworks.com
Mon Jul 7 13:16:56 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: 6f30b27c5ef5 ("arm64: dts: imx8mm: Add Gateworks i.MX 8M Mini Development Kits")
Signed-off-by: Tim Harvey <tharvey at gateworks.com>
---
 arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi
index 5a3b1142ddf4..37db4f0dd505 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-venice-gw700x.dtsi
@@ -418,6 +418,8 @@ &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




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