mmc: card: Kill block requests if card is removed

Kill block requests when the host realizes that the card is
removed from the slot and is sure that subsequent requests
are bound to fail. Do this silently so that the block
layer doesn't output unnecessary error messages.

Change-Id: I25e29ac2fdab999d506ef722966a4725ea584c83
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
[sthumma@codeaurora.org: Fixed merge conflicts]
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 9b64847..b2fb161 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -29,6 +29,8 @@
  */
 static int mmc_prep_request(struct request_queue *q, struct request *req)
 {
+	struct mmc_queue *mq = q->queuedata;
+
 	/*
 	 * We only like normal block requests and discards.
 	 */
@@ -37,6 +39,9 @@
 		return BLKPREP_KILL;
 	}
 
+	if (mq && mmc_card_removed(mq->card))
+		return BLKPREP_KILL;
+
 	req->cmd_flags |= REQ_DONTPREP;
 
 	return BLKPREP_OK;