From f48e6d64a263521a41437d33ee79606ff73e3371 Mon Sep 17 00:00:00 2001
From: Sayali Lokhande <sayalil@codeaurora.org>
Date: Wed, 9 Aug 2017 15:38:28 +0530
Subject: [PATCH] mmc: block: Add error handling in mmc_blk_cmdq_part_switch

mmc_blk_cmdq_part_switch always returned 0 even in case of
failures as errors are not handled in this function.
We need to un-halt cmdq in case it's in halt state when
mmc_switch fails. This change adds error handling code and
returns error in case of any failure.

Change-Id: Icd7ec4b7b53fc56d39dbcea195ae44bf08de17e5
Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
---
 drivers/mmc/card/block.c | 68 ++++++++++++++++++++++++++++++++--------
 1 file changed, 55 insertions(+), 13 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index d39b4056c169..c002fa5ff602 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -3894,6 +3894,7 @@ static inline int mmc_blk_cmdq_part_switch(struct mmc_card *card,
 	struct mmc_host *host = card->host;
 	struct mmc_cmdq_context_info *ctx = &host->cmdq_ctx;
 	u8 part_config = card->ext_csd.part_config;
+	int ret = 0, err = 0;
 
 	if ((main_md->part_curr == md->part_type) &&
 	    (card->part_curr == md->part_type))
@@ -3903,40 +3904,70 @@ static inline int mmc_blk_cmdq_part_switch(struct mmc_card *card,
 		 card->ext_csd.cmdq_support &&
 		 (md->flags & MMC_BLK_CMD_QUEUE)));
 
-	if (!test_bit(CMDQ_STATE_HALT, &ctx->curr_state))
-		WARN_ON(mmc_cmdq_halt(host, true));
+	if (!test_bit(CMDQ_STATE_HALT, &ctx->curr_state)) {
+		ret = mmc_cmdq_halt(host, true);
+		if (ret) {
+			pr_err("%s: %s: halt: failed: %d\n",
+				mmc_hostname(host), __func__,  ret);
+			goto out;
+		}
+	}
 
 	/* disable CQ mode in card */
 	if (mmc_card_cmdq(card)) {
-		WARN_ON(mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+		ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 				 EXT_CSD_CMDQ, 0,
-				  card->ext_csd.generic_cmd6_time));
+				 card->ext_csd.generic_cmd6_time);
+		if (ret) {
+			pr_err("%s: %s: cmdq mode disable failed %d\n",
+				mmc_hostname(host), __func__, ret);
+			goto cmdq_unhalt;
+		}
 		mmc_card_clr_cmdq(card);
 	}
 
 	part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
 	part_config |= md->part_type;
 
-	WARN_ON(mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+	ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
 			 EXT_CSD_PART_CONFIG, part_config,
-			  card->ext_csd.part_time));
+			 card->ext_csd.part_time);
+	if (ret) {
+		pr_err("%s: %s: mmc_switch failure, %d -> %d , err = %d\n",
+			mmc_hostname(host), __func__, main_md->part_curr,
+			md->part_type, ret);
+		goto cmdq_switch;
+	}
 
 	card->ext_csd.part_config = part_config;
 	card->part_curr = md->part_type;
 
 	main_md->part_curr = md->part_type;
 
-	WARN_ON(mmc_blk_cmdq_switch(card, md, true));
-	WARN_ON(mmc_cmdq_halt(host, false));
-
-	return 0;
+cmdq_switch:
+	err = mmc_blk_cmdq_switch(card, md, true);
+	if (err) {
+		pr_err("%s: %s: mmc_blk_cmdq_switch failed: %d\n",
+			mmc_hostname(host), __func__,  err);
+		ret = err;
+	}
+cmdq_unhalt:
+	err = mmc_cmdq_halt(host, false);
+	if (err) {
+		pr_err("%s: %s: unhalt: failed: %d\n",
+			mmc_hostname(host), __func__,  err);
+		ret = err;
+	}
+out:
+	return ret;
 }
 
 static int mmc_blk_cmdq_issue_rq(struct mmc_queue *mq, struct request *req)
 {
-	int ret;
+	int ret, err = 0;
 	struct mmc_blk_data *md = mq->data;
 	struct mmc_card *card = md->queue.card;
+	struct mmc_host *host = card->host;
 	unsigned int cmd_flags = req ? req->cmd_flags : 0;
 
 	mmc_get_card(card);
@@ -3958,9 +3989,20 @@ static int mmc_blk_cmdq_issue_rq(struct mmc_queue *mq, struct request *req)
 
 	ret = mmc_blk_cmdq_part_switch(card, md);
 	if (ret) {
-		pr_err("%s: %s: partition switch failed %d\n",
+		pr_err("%s: %s: partition switch failed %d, resetting cmdq\n",
 				md->disk->disk_name, __func__, ret);
-		goto out;
+
+		mmc_blk_cmdq_reset(host, false);
+		err = mmc_blk_cmdq_part_switch(card, md);
+		if (!err) {
+			pr_err("%s: %s: partition switch success err = %d\n",
+				md->disk->disk_name, __func__, err);
+		} else {
+			pr_err("%s: %s: partition switch failed err = %d\n",
+				md->disk->disk_name, __func__, err);
+			ret = 0;
+			goto out;
+		}
 	}
 
 	if (req) {