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authorDing Wang <justin.wang@spreadtrum.com>2015-05-18 20:14:15 +0800
committerZefan Li <lizefan@huawei.com>2015-10-22 09:20:05 +0800
commitc4b0cf56edc955b00510b36c890ca3fd78df7d67 (patch)
tree8d493b9f46173cc03fabea8972b7b7b534fad8f9
parent5e77bfbbf12d21ac303c802ce41a5f3fa3e1ff79 (diff)
downloadlwn-c4b0cf56edc955b00510b36c890ca3fd78df7d67.tar.gz
lwn-c4b0cf56edc955b00510b36c890ca3fd78df7d67.zip
mmc: card: Fixup request missing in mmc_blk_issue_rw_rq
commit 29535f7b797df35cc9b6b3bca635591cdd3dd2a8 upstream. The current handler of MMC_BLK_CMD_ERR in mmc_blk_issue_rw_rq function may cause new coming request permanent missing when the ongoing request (previoulsy started) complete end. The problem scenario is as follows: (1) Request A is ongoing; (2) Request B arrived, and finally mmc_blk_issue_rw_rq() is called; (3) Request A encounters the MMC_BLK_CMD_ERR error; (4) In the error handling of MMC_BLK_CMD_ERR, suppose mmc_blk_cmd_err() end request A completed and return zero. Continue the error handling, suppose mmc_blk_reset() reset device success; (5) Continue the execution, while loop completed because variable ret is zero now; (6) Finally, mmc_blk_issue_rw_rq() return without processing request B. The process related to the missing request may wait that IO request complete forever, possibly crashing the application or hanging the system. Fix this issue by starting new request when reset success. Signed-off-by: Ding Wang <justin.wang@spreadtrum.com> Fixes: 67716327eec7 ("mmc: block: add eMMC hardware reset support") Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Zefan Li <lizefan@huawei.com>
-rw-r--r--drivers/mmc/card/block.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index c32a9093159a..47a789ea26bc 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1372,9 +1372,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
break;
case MMC_BLK_CMD_ERR:
ret = mmc_blk_cmd_err(md, card, brq, req, ret);
- if (!mmc_blk_reset(md, card->host, type))
- break;
- goto cmd_abort;
+ if (mmc_blk_reset(md, card->host, type))
+ goto cmd_abort;
+ if (!ret)
+ goto start_new_req;
+ break;
case MMC_BLK_RETRY:
if (retry++ < 5)
break;