[PATCH v1 1/2] scsi: ufs: Fix unbalanced scsi_block_reqs_cnt caused by ufshcd_hold()

[Can Guo]

The scsi_block_reqs_cnt increased in ufshcd_hold() is supposed to be
decreased back in ufshcd_ungate_work() in a paired way. However, if
specific ufshcd_hold/release sequences are met, it is possible that
scsi_block_reqs_cnt is increased twice but only one ungate work is
queued. To make sure scsi_block_reqs_cnt is handled by ufshcd_hold() and
ufshcd_ungate_work() in a paired way, increase it only if queue_work()
returns true.

Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Reviewed-by: Hongwu Su <hongwus@xxxxxxxxxxxxxx>
---
 drivers/scsi/ufs/ufshcd.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 847f355..efa7d86 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1634,12 +1634,12 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
 		 */
 		/* fallthrough */
 	case CLKS_OFF:
-		ufshcd_scsi_block_requests(hba);
 		hba->clk_gating.state = REQ_CLKS_ON;
 		trace_ufshcd_clk_gating(dev_name(hba->dev),
 					hba->clk_gating.state);
-		queue_work(hba->clk_gating.clk_gating_workq,
-			   &hba->clk_gating.ungate_work);
+		if (queue_work(hba->clk_gating.clk_gating_workq,
+			       &hba->clk_gating.ungate_work))
+			ufshcd_scsi_block_requests(hba);
 		/*
 		 * fall through to check if we should wait for this
 		 * work to be done or not.
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.