arm64: dts: amlogic: t7: khadas-vim4: allow the SD card to be power cycled

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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: 8c45bf9ae4 ("arm64: dts: amlogic: t7: khadas-vim4: Add power regulators")
Signed-off-by: Lucas Tanure <tanure@linux.com>
Assisted-by: Claude:claude-fable-5
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260823115335.102219-3-tanure@linux.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

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Lucas Tanure 2026-08-23 12:53:35 +01:00 • committed by Neil Armstrong

parent 882de800bf

commit c793a084ab

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arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts

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