[PATCH v3 3/4] mmc: meson-gx: report busy from DAT0 alone

[Igor Velkov via B4 Relay]

From: Igor Velkov <iav at iav.lv>

meson_mmc_card_busy() reports busy only while DAT0..3 are all low. A
busy card drives DAT0 low and leaves DAT1..3 to the pull-ups, and the
callback is defined as "Check if the card is pulling dat[0] low". So a
busy card is reported free, and the core, which prefers card_busy over
CMD13 in mmc_busy_cb(), stops polling after CMD6 and erase at once. The
controller hides this on R1b commands, where it waits for busy itself.
Once max_busy_timeout is reported, the core sends the longer waits, the
120 s BKOPS and 240 s sanitize switches among them, as R1 and has only
the polling left.

Look at DAT0 only, as sdhci_card_busy() does. The checks around the
voltage switch in mmc_set_uhs_voltage() still hold: the card drives
DAT0..3 low together after CMD11 and keeps them low together on
failure.

Fixes: 186cd8b7f586 ("mmc: meson-gx: implement card_busy callback")
Assisted-by: LLM
Signed-off-by: Igor Velkov <iav at iav.lv>
---
 drivers/mmc/host/meson-gx-mmc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index dd246ad63653..abdb12e5f997 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -1095,8 +1095,8 @@ static int meson_mmc_card_busy(struct mmc_host *mmc)
 
 	regval = readl(host->regs + SD_EMMC_STATUS);
 
-	/* We are only interrested in lines 0 to 3, so mask the other ones */
-	return !(FIELD_GET(STATUS_DATI, regval) & 0xf);
+	/* The card signals busy on DAT0 alone. */
+	return !(FIELD_GET(STATUS_DATI, regval) & BIT(0));
 }
 
 static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)

-- 
2.43.0