Hi All, Friendly ping on the patch below - it has been about a month with no feedback. Would appreciate any review at your earliest convenience.
Thanks, Tanmay On 5/15/2026 12:24 AM, Tanmay Kathpalia wrote:
When a UHS card successfully negotiates 1.8V signaling during normal initialization, the host voltage switch is performed as part of the ACMD41 handshake. Without this fix, the warm-reboot recovery path would fire again immediately after, switching the host voltage a second time unnecessarily. Add a check so the recovery path is only entered when the voltage switch was not already performed during the current initialization session. Fixes: 906ee6785b1c ("mmc: sd: Handle UHS-I voltage signaling without power cycle") Signed-off-by: Tanmay Kathpalia <[email protected]> --- drivers/mmc/mmc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 7dadff27abe..10d8a37d2a8 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -2720,10 +2720,11 @@ static int mmc_startup(struct mmc *mmc)#if CONFIG_IS_ENABLED(MMC_UHS_SUPPORT)/* - * If the card has already switched to 1.8V signaling, then - * set the signal voltage to 1.8V. + * If voltage switch was skipped during ACMD41 but the card is + * already at 1.8V (retained from a previous session, e.g. warm + * reboot), re-configure the host to match. */ - if (mmc_sd_card_using_v18(mmc)) { + if (!(mmc->ocr & OCR_S18R) && mmc_sd_card_using_v18(mmc)) { /* * During a signal voltage level switch, the clock must be gated * for 5 ms according to the SD spec.
