omap_hsmmc: cater for weird CMD6 behaviour

Sometimes the controller unexpectedly produces a TC (transfer complete)
interrupt before the CC (command complete) interrupt for command 6
(SWITCH).  This is a problem because the CC interrupt can get mixed up
with the next request.  Add a hack for CMD6.

Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Ian Molton <ian@mnementh.co.uk>
Cc: "Roberto A. Foglietta" <roberto.foglietta@gmail.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Denis Karpov <ext-denis.2.karpov@nokia.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Philip Langdale <philipl@overt.org>
Cc: "Madhusudhan" <madhu.cr@ti.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/mmc/host/omap_hsmmc.c

@@ -481,6 +481,13 @@ mmc_omap_xfer_done(struct mmc_omap_host *host, struct mmc_data *data)
 	if (!data) {
 		struct mmc_request *mrq = host->mrq;
 
+		/* TC before CC from CMD6 - don't know why, but it happens */
+		if (host->cmd && host->cmd->opcode == 6 &&
+		    host->response_busy) {
+			host->response_busy = 0;
+			return;
+		}
+
 		host->mrq = NULL;
 		mmc_request_done(host->mmc, mrq);
 		return;