[PATCH 4/4] ARM: dts: Fix-up EMMC2 controller's frequency

Nicolas Saenz Julienne nsaenz at kernel.org
Mon Mar 22 18:58:17 GMT 2021


From: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>

Force emmc2's frequency to 150MHz as the default 100MHz (set by FW)
seems to interfere with the VPU clock when setup at frequencies bigger
than 500MHz (a pretty common case). This ends up causing unwarranted
SDHCI CMD hangs  when no SD card is present.

Signed-off-by: Nicolas Saenz Julienne <nsaenz at kernel.org>
---
 arch/arm/boot/dts/bcm2711-rpi-4-b.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
index 3b4ab947492a..9aa8408d9960 100644
--- a/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
+++ b/arch/arm/boot/dts/bcm2711-rpi-4-b.dts
@@ -257,6 +257,12 @@ &emmc2 {
 	vqmmc-supply = <&sd_io_1v8_reg>;
 	vmmc-supply = <&sd_vcc_reg>;
 	broken-cd;
+	/*
+	 * Force the frequency to 150MHz as the default 100MHz seems to
+	 * interfere with the VPU clock when setup at frequencies bigger than
+	 * 500MHz, causing unwarranted CMD hangs.
+	 */
+	clock-frequency = <150000000>;
 	status = "okay";
 };
 
-- 
2.30.2




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