[PATCH 1/3] ufs: core: Fix ufshcd_mcq_force_compl_one()

[Bart Van Assche <bvanassche@acm.org>]

There are two issues with the code in ufshcd_mcq_compl_all_cqes_lock():
- The completion queue is processed without checking first whether it is
  empty.
- It is attempted to process hwq->max_entries while there can be at most
  hwq->max_entries - 1 entries on a completion queue.

Fix this by replacing the only ufshcd_mcq_compl_all_cqes_lock() call with
a call to ufshcd_mcq_poll_cqe_lock().

Fixes: ab248643d3d6 ("scsi: ufs: core: Add error handling for MCQ mode")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/ufs/core/ufs-mcq.c     | 18 ------------------
 drivers/ufs/core/ufshcd-priv.h |  2 --
 drivers/ufs/core/ufshcd.c      |  2 +-
 3 files changed, 1 insertion(+), 21 deletions(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 1b3062577945..8ccde4571859 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -322,24 +322,6 @@ static void ufshcd_mcq_process_cqe(struct ufs_hba *hba,
 	}
 }
 
-void ufshcd_mcq_compl_all_cqes_lock(struct ufs_hba *hba,
-				    struct ufs_hw_queue *hwq)
-{
-	unsigned long flags;
-	u32 entries = hwq->max_entries;
-
-	spin_lock_irqsave(&hwq->cq_lock, flags);
-	while (entries > 0) {
-		ufshcd_mcq_process_cqe(hba, hwq);
-		ufshcd_mcq_inc_cq_head_slot(hwq);
-		entries--;
-	}
-
-	ufshcd_mcq_update_cq_tail_slot(hwq);
-	hwq->cq_head_slot = hwq->cq_tail_slot;
-	spin_unlock_irqrestore(&hwq->cq_lock, flags);
-}
-
 unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
 				       struct ufs_hw_queue *hwq)
 {
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index 0a72148cb053..96fcd935790b 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -71,8 +71,6 @@ int ufshcd_get_hba_mac(struct ufs_hba *hba);
 int ufshcd_mcq_memory_alloc(struct ufs_hba *hba);
 struct ufs_hw_queue *ufshcd_mcq_req_to_hwq(struct ufs_hba *hba,
 					   struct request *req);
-void ufshcd_mcq_compl_all_cqes_lock(struct ufs_hba *hba,
-				    struct ufs_hw_queue *hwq);
 bool ufshcd_cmd_inflight(struct scsi_cmnd *cmd);
 int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag);
 int ufshcd_mcq_abort(struct scsi_cmnd *cmd);
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index cb81aa94d5c4..28b8e7291394 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5855,7 +5855,7 @@ 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);
+	ufshcd_mcq_poll_cqe_lock(hba, hwq);
 
 	/*
 	 * For those cmds of which the cqes are not present in the cq, complete