mmc: tmio_mmc: fix CMD irq handling

With current code card insert/eject interrupts will acknowledge outstanding
commands. Normally this seems to be no problem, however if the hardware gets
stuck and no interrupts for CMD_TIMEOUT or CMD_RESPEND are generated, then
inserting and ejecting cards will falsely acknowledge outstanding commands
from the core.

This patch changes the behavior so that CMDs are only acked, if
CMD_TIMEOUT or CMD_RESPEND is received.
Signed-off-by: Arnd Hannemann <arnd@arndnet.de>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/tmio_mmc.c

@@ -727,8 +727,10 @@ static irqreturn_t tmio_mmc_irq(int irq, void *devid)
  */
 
 		/* Command completion */
-		if (ireg & TMIO_MASK_CMD) {
-			ack_mmc_irqs(host, TMIO_MASK_CMD);
+		if (ireg & (TMIO_STAT_CMDRESPEND | TMIO_STAT_CMDTIMEOUT)) {
+			ack_mmc_irqs(host,
+				     TMIO_STAT_CMDRESPEND |
+				     TMIO_STAT_CMDTIMEOUT);
 			tmio_mmc_cmd_irq(host, status);
 		}