mmc: block: fix boot partition switch error path

In the case of a switch error, do not update partition config as though
the switch succeeded, and ensure blk_end_request is called on the
failed request.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andrei Warkentin <andrey.warkentin@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/card/block.c

@@ -447,18 +447,23 @@ static inline int mmc_blk_part_switch(struct mmc_card *card,
 {
 	int ret;
 	struct mmc_blk_data *main_md = mmc_get_drvdata(card);
+
 	if (main_md->part_curr == md->part_type)
 		return 0;
 
 	if (mmc_card_mmc(card)) {
-		card->ext_csd.part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
-		card->ext_csd.part_config |= md->part_type;
+		u8 part_config = card->ext_csd.part_config;
+
+		part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
+		part_config |= md->part_type;
 
 		ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
-				 EXT_CSD_PART_CONFIG, card->ext_csd.part_config,
+				 EXT_CSD_PART_CONFIG, part_config,
 				 card->ext_csd.part_time);
 		if (ret)
 			return ret;
+
+		card->ext_csd.part_config = part_config;
 	}
 
 	main_md->part_curr = md->part_type;
@@ -1273,6 +1278,11 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 
 	ret = mmc_blk_part_switch(card, md);
 	if (ret) {
+		if (req) {
+			spin_lock_irq(&md->lock);
+			__blk_end_request_all(req, -EIO);
+			spin_unlock_irq(&md->lock);
+		}
 		ret = 0;
 		goto out;
 	}