[PATCH 2/2] arm64: dts: amlogic: t7: khadas-vim4: allow the SD card to be power cycled

Lucas Tanure tanure at linux.com
Tue Aug 18 12:11:59 PDT 2026


SD cards start at 3.3V and switch to 1.8V to reach UHS-I speeds. Some
cards refuse that switch, and the SD specification says the only way
to recover is to power the card off and start again.

SD_3V3 is marked regulator-always-on, so the supply never goes off,
the card stays stuck half way through the switch, and the MMC core
retries forever:

  mmc1: error -95 whilst initialising SD card

Drop regulator-always-on. regulator-boot-on still turns the supply on
at boot, and a card that refuses the switch now falls back to high
speed instead of failing to initialise.

Fixes: 8c45bf9ae4ef ("arm64: dts: amlogic: t7: khadas-vim4: Add power regulators")
Signed-off-by: Lucas Tanure <tanure at linux.com>
Assisted-by: Claude:claude-fable-5
---
 arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
index 677069e58f30..3f53630e107f 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
@@ -71,7 +71,6 @@ sd_3v3: regulator-sdcard-3v3 {
 		vin-supply = <&vddao_3v3>;
 		gpio = <&gpio GPIOD_11 GPIO_ACTIVE_LOW>;
 		regulator-boot-on;
-		regulator-always-on;
 	};
 
 	sdio_pwrseq: sdio-pwrseq {
-- 
2.55.0




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