ARM: 6980/1: mmci: use StartBitErr to detect bad connections

Stresstesting insert/remove of SD-cards can trigger
a StartBitErr. This made the driver to hang in forever
waiting for a non ocurring data timeout.

This bit and interrupt is documented in the original
PL180 TRM, just never implemented until now.

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Linus Walleij <linus.walleij@stericsson.com>
Reviewed-by: Jonas Aberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/mmc/host/mmci.c

@@ -582,6 +582,8 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 			data->error = -EILSEQ;
 		} else if (status & MCI_DATATIMEOUT) {
 			data->error = -ETIMEDOUT;
+		} else if (status & MCI_STARTBITERR) {
+			data->error = -ECOMM;
 		} else if (status & MCI_TXUNDERRUN) {
 			data->error = -EIO;
 		} else if (status & MCI_RXOVERRUN) {

drivers/mmc/host/mmci.h

@@ -86,6 +86,7 @@
 #define MCI_CMDRESPEND		(1 << 6)
 #define MCI_CMDSENT		(1 << 7)
 #define MCI_DATAEND		(1 << 8)
+#define MCI_STARTBITERR		(1 << 9)
 #define MCI_DATABLOCKEND	(1 << 10)
 #define MCI_CMDACTIVE		(1 << 11)
 #define MCI_TXACTIVE		(1 << 12)
@@ -112,6 +113,7 @@
 #define MCI_CMDRESPENDCLR	(1 << 6)
 #define MCI_CMDSENTCLR		(1 << 7)
 #define MCI_DATAENDCLR		(1 << 8)
+#define MCI_STARTBITERRCLR	(1 << 9)
 #define MCI_DATABLOCKENDCLR	(1 << 10)
 /* Extended status bits for the ST Micro variants */
 #define MCI_ST_SDIOITC		(1 << 22)
@@ -127,6 +129,7 @@
 #define MCI_CMDRESPENDMASK	(1 << 6)
 #define MCI_CMDSENTMASK		(1 << 7)
 #define MCI_DATAENDMASK		(1 << 8)
+#define MCI_STARTBITERRMASK	(1 << 9)
 #define MCI_DATABLOCKENDMASK	(1 << 10)
 #define MCI_CMDACTIVEMASK	(1 << 11)
 #define MCI_TXACTIVEMASK	(1 << 12)
@@ -150,7 +153,7 @@
 #define MCI_IRQENABLE	\
 	(MCI_CMDCRCFAILMASK|MCI_DATACRCFAILMASK|MCI_CMDTIMEOUTMASK|	\
 	MCI_DATATIMEOUTMASK|MCI_TXUNDERRUNMASK|MCI_RXOVERRUNMASK|	\
-	MCI_CMDRESPENDMASK|MCI_CMDSENTMASK)
+	MCI_CMDRESPENDMASK|MCI_CMDSENTMASK|MCI_STARTBITERRMASK)
 
 /* These interrupts are directed to IRQ1 when two IRQ lines are available */
 #define MCI_IRQ1MASK \