[PATCH v2 1/6] mmc: sdhci: clear auto cmd setting bits for no data cmds

[b29396@freescale.com (Dong Aisheng)]

The auto cmd settings bits should be cleared before sending new commands
or we may receive command timeout error for normal commands due to wrongly
pre-sent auto cmd.

e.g. we receive CMD13 timeout error due to ACMD23 is wrongly enabled
by former data commands.

mmc2: new high speed DDR MMC card at address 0001
mmcblk1: mmc2:0001 SEM08G 7.39 GiB
mmcblk1boot0: mmc2:0001 SEM08G partition 1 2.00 MiB
mmcblk1boot1: mmc2:0001 SEM08G partition 2 2.00 MiB
mmcblk1rpmb: mmc2:0001 SEM08G partition 3 128 KiB
 mmcblk1: p1 p2 p3 p4 < p5 p6 p7 >
mmc2: Timeout waiting for hardware interrupt.
 mmcblk1boot1: unknown partition table
mmc2: Timeout waiting for hardware interrupt.
 mmcblk1boot0: unknown partition table

Signed-off-by: Dong Aisheng <b29396@freescale.com>
---
 drivers/mmc/host/sdhci.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 68b3cac..22eab3a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -903,8 +903,13 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
 	u16 mode;
 	struct mmc_data *data = cmd->data;
 
-	if (data == NULL)
+	if (data == NULL) {
+		/* clear Auto CMD settings for no data CMDs */
+		mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
+		sdhci_writew(host, mode & ~(SDHCI_TRNS_AUTO_CMD12 |
+				SDHCI_TRNS_AUTO_CMD23), SDHCI_TRANSFER_MODE);
 		return;
+	}
 
 	WARN_ON(!host->data);
 
-- 
1.7.2.rc3