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From: Kiwoong Kim <kwmad.kim@samsung.com>
To: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
	alim.akhtar@samsung.com, avri.altman@wdc.com, bvanassche@acm.org,
	jejb@linux.ibm.com, martin.petersen@oracle.com, beanhuo@micron.com,
	adrian.hunter@intel.com, h10.kim@samsung.com, hy50.seo@samsung.com,
	sh425.lee@samsung.com, kwangwon.min@samsung.com, junwoo80.lee@samsung.com,
	wkon.kim@samsung.com
Cc: Kiwoong Kim <kwmad.kim@samsung.com>
Subject: [PATCH v1] ufs: get target SQ entry within critical section
Date: Thu,  4 Jan 2024 10:24:50 +0900
Message-Id: <1704331491-115325-1-git-send-email-kwmad.kim@samsung.com>
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References: <CGME20240104012454epcas2p36b58220b4c89ee72f1e095b34d329be2@epcas2p3.samsung.com>
Precedence: bulk

In IO centric scenarios, especially during a period that
many IO requests are submitted to a same HW queue at the same
time, it's found that one reqeust overwrote a SQ entry
that had been already occupied by another request submitted
in the past. And it eventually led to command timed-out
because one of two requests were overwritten, which could not
be completed.

[   74.995185][  T176] exynos-ufs 17100000.ufs: ufshcd_abort: Device abort task at tag 30

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
---
 drivers/ufs/core/ufshcd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 7bc3fc4..da1a9c0 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2199,9 +2199,10 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag,
 	if (is_mcq_enabled(hba)) {
 		int utrd_size = sizeof(struct utp_transfer_req_desc);
 		struct utp_transfer_req_desc *src = lrbp->utr_descriptor_ptr;
-		struct utp_transfer_req_desc *dest = hwq->sqe_base_addr + hwq->sq_tail_slot;
+		struct utp_transfer_req_desc *dest;
 
 		spin_lock(&hwq->sq_lock);
+		dest = hwq->sqe_base_addr + hwq->sq_tail_slot;
 		memcpy(dest, src, utrd_size);
 		ufshcd_inc_sq_tail(hwq);
 		spin_unlock(&hwq->sq_lock);
-- 
2.7.4