[PATCH] mmc: xenon_sdhci: remove wait_dat0 SDHCI OP

[Robert Marko]

Generic SDHCI driver received support for checking the busy status by
polling the DAT[0] level instead of waiting for the worst MMC switch time.

Unfortunately, it appears that this does not work for Xenon controllers
despite being a part of the standard SDHCI registers and the Armada 3720
datasheet itself telling that BIT(20) is useful for detecting the DAT[0]
busy signal.

I have tried increasing the timeout value, but I have newer managed to
catch DAT_LEVEL bits change from 0 at all.

This issue appears to hit most if not all SoC-s supported by Xenon driver,
at least A3720, A8040 and CN9130 have non working eMMC currently.

So, until a better solution is found drop the wait_dat0 OP for Xenon.
I was able to only test it on A3720, but it should work for others as well.

Fixes: 40e6f52454fc ("drivers: mmc: Add wait_dat0 support for sdhci driver")
Signed-off-by: Robert Marko <robert.marko at sartura.hr>
---
 drivers/mmc/xenon_sdhci.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/xenon_sdhci.c b/drivers/mmc/xenon_sdhci.c
index e292f2903d..2f8805096c 100644
--- a/drivers/mmc/xenon_sdhci.c
+++ b/drivers/mmc/xenon_sdhci.c
@@ -439,6 +439,8 @@ static const struct sdhci_ops xenon_sdhci_ops = {
 	.set_ios_post = xenon_sdhci_set_ios_post
 };
 
+static struct dm_mmc_ops xenon_mmc_ops;
+
 static int xenon_sdhci_probe(struct udevice *dev)
 {
 	struct xenon_sdhci_plat *plat = dev_get_plat(dev);
@@ -452,6 +454,9 @@ static int xenon_sdhci_probe(struct udevice *dev)
 	host->mmc->dev = dev;
 	upriv->mmc = host->mmc;
 
+	xenon_mmc_ops = sdhci_ops;
+	xenon_mmc_ops.wait_dat0 = NULL;
+
 	/* Set quirks */
 	host->quirks = SDHCI_QUIRK_WAIT_SEND_CMD | SDHCI_QUIRK_32BIT_DMA_ADDR;
 
@@ -568,7 +573,7 @@ U_BOOT_DRIVER(xenon_sdhci_drv) = {
 	.id		= UCLASS_MMC,
 	.of_match	= xenon_sdhci_ids,
 	.of_to_plat = xenon_sdhci_of_to_plat,
-	.ops		= &sdhci_ops,
+	.ops		= &xenon_mmc_ops,
 	.bind		= xenon_sdhci_bind,
 	.probe		= xenon_sdhci_probe,
 	.remove		= xenon_sdhci_remove,
-- 
2.35.1