scsi: ufs: Minor adjustments to error handling

In error handling prepare stage, after SCSI requests are blocked, do a
down/up_write(clk_scaling_lock) to clean up the queuecommand() path.
Meanwhile, stop eeh_work in case it disturbs error recovery. Moreover,
reset ufshcd_state at the entrance of ufshcd_probe_hba(), since it may be
called multiple times during error recovery.

Link: https://lore.kernel.org/r/1614145010-36079-2-git-send-email-cang@codeaurora.org
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -4987,6 +4987,7 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 			 * UFS device needs urgent BKOPs.
 			 */
 			if (!hba->pm_op_in_progress &&
+			    !ufshcd_eh_in_progress(hba) &&
 			    ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) &&
 			    schedule_work(&hba->eeh_work)) {
 				/*
@@ -5784,13 +5785,20 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
 			ufshcd_suspend_clkscaling(hba);
 		ufshcd_clk_scaling_allow(hba, false);
 	}
+	ufshcd_scsi_block_requests(hba);
+	/* Drain ufshcd_queuecommand() */
+	down_write(&hba->clk_scaling_lock);
+	up_write(&hba->clk_scaling_lock);
+	cancel_work_sync(&hba->eeh_work);
 }
 
 static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
 {
+	ufshcd_scsi_unblock_requests(hba);
 	ufshcd_release(hba);
 	if (ufshcd_is_clkscaling_supported(hba))
 		ufshcd_clk_scaling_suspend(hba, false);
+	ufshcd_clear_ua_wluns(hba);
 	pm_runtime_put(hba->dev);
 }
 
@@ -5882,8 +5890,8 @@ static void ufshcd_err_handler(struct work_struct *work)
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 	ufshcd_err_handling_prepare(hba);
 	spin_lock_irqsave(hba->host->host_lock, flags);
-	ufshcd_scsi_block_requests(hba);
-	hba->ufshcd_state = UFSHCD_STATE_RESET;
+	if (hba->ufshcd_state != UFSHCD_STATE_ERROR)
+		hba->ufshcd_state = UFSHCD_STATE_RESET;
 
 	/* Complete requests that have door-bell cleared by h/w */
 	ufshcd_complete_requests(hba);
@@ -6042,12 +6050,8 @@ static void ufshcd_err_handler(struct work_struct *work)
 	}
 	ufshcd_clear_eh_in_progress(hba);
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
-	ufshcd_scsi_unblock_requests(hba);
 	ufshcd_err_handling_unprepare(hba);
 	up(&hba->host_sem);
-
-	if (!err && needs_reset)
-		ufshcd_clear_ua_wluns(hba);
 }
 
 /**
@@ -7858,6 +7862,8 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async)
 	unsigned long flags;
 	ktime_t start = ktime_get();
 
+	hba->ufshcd_state = UFSHCD_STATE_RESET;
+
 	ret = ufshcd_link_startup(hba);
 	if (ret)
 		goto out;