Re: [PATCH 4/4] ARM: dts: Fix-up EMMC2 controller's frequency
From: Stefan Wahren <hidden>
Date: 2021-03-24 15:17:00
Also in:
linux-arm-kernel, linux-mmc, lkml
Hi Nicolas, Am 22.03.21 um 19:58 schrieb Nicolas Saenz Julienne:
quoted hunk ↗ jump to hunk
From: Nicolas Saenz Julienne <redacted> 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@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>;
i don't want to bike-shed here, but is there any chance to solve this in clk-bcm2835 in a less hacky way? Anyway thank for taking care of this. Best regards
status = "okay"; };