[PATCH] arm: dts: an7581: set r_smpl for MMC in U-Boot
Ray Liu
ray.xy.liu at gmail.com
Fri Jan 2 14:25:00 CET 2026
When booting from SPI, the ROM code does not initialize the MMC
controller on AN7581. As a result, the first MMC initialization
is performed by U-Boot.
In this case, the r_smpl bit is left uninitialized, which may
cause incorrect sampling timing during early MMC access.
Set the r_smpl bit explicitly in the U-Boot device tree to ensure
reliable MMC initialization.
This change is limited to the U-Boot-specific device tree.
The Linux MMC driver already performs runtime delay detection
and does not require a fixed r_smpl setting.
Signed-off-by: Ray Liu <ray.xy.liu at gmail.com>
---
arch/arm/dts/an7581-u-boot.dtsi | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm/dts/an7581-u-boot.dtsi b/arch/arm/dts/an7581-u-boot.dtsi
index a9297ca6503..7fc71d471c4 100644
--- a/arch/arm/dts/an7581-u-boot.dtsi
+++ b/arch/arm/dts/an7581-u-boot.dtsi
@@ -84,6 +84,7 @@
reg = <0x0 0x1fa0e000 0x0 0x1000>,
<0x0 0x1fa0c000 0x0 0x60>;
interrupts = <GIC_SPI 170 IRQ_TYPE_LEVEL_HIGH>;
+ r_smpl = <1>;
clocks = <&scuclk EN7581_CLK_EMMC>, <&clk25m>;
clock-names = "source", "hclk";
bus-width = <4>;
--
2.34.1
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