FAILED: patch "[PATCH] scsi: ufs: core: Decouple CQ sweep from request iterator in" failed to apply to 6.12-stable tree

PATCH New [email protected] 2 participants 2 messages Oct 12 – Oct 13

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2026-10-12 15:22 UTC #0 lore raw

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 469fa055664bfd8717b087a80d59c03055789c17
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026101229-boots-shortcut-fa1c@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 469fa055664bfd8717b087a80d59c03055789c17 Mon Sep 17 00:00:00 2001
From: Stanley Jhu <[email protected]>
Date: Mon, 28 Sep 2026 11:58:16 +0800
Subject: [PATCH] scsi: ufs: core: Decouple CQ sweep from request iterator in
MCQ

In MCQ mode, ufshcd_mcq_compl_pending_transfer() uses blk_mq_tagset_busy_iter() to iterate over busy requests during error recovery and host reset. However, both iterator callbacks perform whole-queue operations redundantly for each visited request:

- force_compl == true: ufshcd_mcq_force_compl_one() calls ufshcd_mcq_compl_all_cqes_lock() on every busy request, sweeping the entire completion ring (hwq->max_entries slots) once per active request under spin_lock_irqsave even though the first sweep already cleared all completion entries.

- force_compl == false: ufshcd_mcq_compl_one() acquires cq_lock and polls CQTPy over MMIO via ufshcd_mcq_poll_cqe_lock() for every busy request without doing any per-request work.

Sweep or poll each hardware queue (hba->uhq[i]) once at the start of ufshcd_mcq_compl_pending_transfer(). When force_compl is true, run blk_mq_tagset_busy_iter() afterward to complete residual in-flight requests with DID_REQUEUE, and remove the now-unused ufshcd_mcq_compl_one() callback.

Fixes ab248643d3d6 ("scsi: ufs: core: Add error handling for MCQ mode")

Cc [email protected]

Reviewed-by Bart Van Assche <[email protected]>

Signed-off-by Stanley Jhu <[email protected]>

Reviewed-by Peter Wang <[email protected]>

Link https://patch.msgid.link/[email protected] open here

Signed-off-by Martin K. Petersen (Oracle) <[email protected]>

drivers/ufs/core/ufshcd.c +12 ~~-19~~

index 79b6a2d9b522..ca8329052cbc 100644
@@ -6044,8 +6044,6 @@ static bool ufshcd_mcq_force_compl_one(struct request *rq, void *priv)
 	if (blk_mq_is_reserved_rq(rq) || !hwq)
 		return true;
 
-	ufshcd_mcq_compl_all_cqes_lock(hba, hwq);
-
 	/*
 	 * For those cmds of which the cqes are not present in the cq, complete
 	 * them explicitly.

@@ -6061,19 +6059,6 @@ static bool ufshcd_mcq_force_compl_one(struct request *rq, void *priv)
 	return true;
 }
 
-static bool ufshcd_mcq_compl_one(struct request *rq, void *priv)
-{
-	struct scsi_device *sdev = rq->q->queuedata;
-	struct Scsi_Host *shost = sdev->host;
-	struct ufs_hba *hba = shost_priv(shost);
-	struct ufs_hw_queue *hwq = ufshcd_mcq_req_to_hwq(hba, rq);
-
-	if (!blk_mq_is_reserved_rq(rq) && hwq)
-		ufshcd_mcq_poll_cqe_lock(hba, hwq);
-
-	return true;
-}
-
 /**
  * ufshcd_mcq_compl_pending_transfer - MCQ mode function. It is
  * invoked from the error handler context or ufshcd_host_reset_and_restore()

@@ -6088,10 +6073,18 @@ static bool ufshcd_mcq_compl_one(struct request *rq, void *priv)
 static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba,
 					      bool force_compl)
 {
-	blk_mq_tagset_busy_iter(&hba->host->tag_set,
-				force_compl ? ufshcd_mcq_force_compl_one :
-					      ufshcd_mcq_compl_one,
-				NULL);
+	int i;
+
+	for (i = 0; i < hba->nr_hw_queues; i++) {
+		if (force_compl)
+			ufshcd_mcq_compl_all_cqes_lock(hba, &hba->uhq[i]);
+		else
+			ufshcd_mcq_poll_cqe_lock(hba, &hba->uhq[i]);
+	}
+
+	if (force_compl)
+		blk_mq_tagset_busy_iter(&hba->host->tag_set,
+					ufshcd_mcq_force_compl_one, NULL);
 }
 
 /**

Sasha Levin

maintainer

2026-10-13 15:49 UTC #1 lore raw

PATCH 1/1 scsi: ufs: core: Decouple CQ sweep from request iterator in MCQ

From: Stanley Jhu <[email protected]>

[ Upstream commit 469fa055664bfd8717b087a80d59c03055789c17 ]

- force_compl == false: ufshcd_mcq_compl_one() acquires cq_lock and polls CQTPy over MMIO via ufshcd_mcq_poll_cqe_lock() for every busy request without doing any per-request work.

Fixes ab248643d3d6 ("scsi: ufs: core: Add error handling for MCQ mode")

Cc [email protected]

Reviewed-by Bart Van Assche <[email protected]>

Signed-off-by Stanley Jhu <[email protected]>

Reviewed-by Peter Wang <[email protected]>

Link https://patch.msgid.link/[email protected] open here

Signed-off-by Martin K. Petersen (Oracle) <[email protected]>

[ sashal: adapted blk_mq_tagset_busy_iter() callback changes to the existing tag-based completion loop ]

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/ufs/core/ufshcd.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

drivers/ufs/core/ufshcd.c +21 ~~-16~~

index 22f4f5f08e74a..9c2f407da28a1 100644
@@ -5685,7 +5685,17 @@ static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba,
 	struct ufshcd_lrb *lrbp;
 	struct scsi_cmnd *cmd;
 	unsigned long flags;
-	int tag;
+	int tag, i;
+
+	for (i = 0; i < hba->nr_hw_queues; i++) {
+		if (force_compl)
+			ufshcd_mcq_compl_all_cqes_lock(hba, &hba->uhq[i]);
+		else
+			ufshcd_mcq_poll_cqe_lock(hba, &hba->uhq[i]);
+	}
+
+	if (!force_compl)
+		return;
 
 	for (tag = 0; tag < hba->nutrs; tag++) {
 		lrbp = &hba->lrb[tag];

@@ -5698,22 +5708,17 @@ static void ufshcd_mcq_compl_pending_transfer(struct ufs_hba *hba,
 		if (!hwq)
 			continue;
 
-		if (force_compl) {
-			ufshcd_mcq_compl_all_cqes_lock(hba, hwq);
-			/*
-			 * For those cmds of which the cqes are not present
-			 * in the cq, complete them explicitly.
-			 */
-			spin_lock_irqsave(&hwq->cq_lock, flags);
-			if (cmd && !test_bit(SCMD_STATE_COMPLETE, &cmd->state)) {
-				set_host_byte(cmd, DID_REQUEUE);
-				ufshcd_release_scsi_cmd(hba, lrbp);
-				scsi_done(cmd);
-			}
-			spin_unlock_irqrestore(&hwq->cq_lock, flags);
-		} else {
-			ufshcd_mcq_poll_cqe_lock(hba, hwq);
+		/*
+		 * For those cmds of which the cqes are not present
+		 * in the cq, complete them explicitly.
+		 */
+		spin_lock_irqsave(&hwq->cq_lock, flags);
+		if (cmd && !test_bit(SCMD_STATE_COMPLETE, &cmd->state)) {
+			set_host_byte(cmd, DID_REQUEUE);
+			ufshcd_release_scsi_cmd(hba, lrbp);
+			scsi_done(cmd);
 		}
+		spin_unlock_irqrestore(&hwq->cq_lock, flags);
 	}
 }

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2.53.0