From: Peter Wang <peter.wang@mediatek.com>
Date: Wed, 8 Oct 2025 06:55:43 +0000 (+0800)
Subject: scsi: ufs: core: Fix error handler host_sem issue
X-Git-Tag: v6.18-rc4~18^2~3
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e23ef4f22db30a1e49c8b060e4ebc9dc9ca99c49;p=thirdparty%2Flinux.git

scsi: ufs: core: Fix error handler host_sem issue

Fix the issue where host_sem is not released due to a new return path in
commit f966e02ae521 ("scsi: ufs: core: Fix runtime suspend error
deadlock").

Check pm_op_in_progress before acquiring hba->host_sem to prevent
deadlocks and ensure proper resource management during error
handling. Add comment for use ufshcd_rpm_get_noresume() to safely
perform link recovery without interfering with ongoing PM operations.

Fixes: f966e02ae521 ("scsi: ufs: core: Fix runtime suspend error deadlock")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251008065651.1589614-2-peter.wang@mediatek.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 8339fec975b9..8f4e884892a9 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -6673,6 +6673,20 @@ static void ufshcd_err_handler(struct work_struct *work)
 		 hba->saved_uic_err, hba->force_reset,
 		 ufshcd_is_link_broken(hba) ? "; link is broken" : "");
 
+	/*
+	 * Use ufshcd_rpm_get_noresume() here to safely perform link recovery
+	 * even if an error occurs during runtime suspend or runtime resume.
+	 * This avoids potential deadlocks that could happen if we tried to
+	 * resume the device while a PM operation is already in progress.
+	 */
+	ufshcd_rpm_get_noresume(hba);
+	if (hba->pm_op_in_progress) {
+		ufshcd_link_recovery(hba);
+		ufshcd_rpm_put(hba);
+		return;
+	}
+	ufshcd_rpm_put(hba);
+
 	down(&hba->host_sem);
 	spin_lock_irqsave(hba->host->host_lock, flags);
 	if (ufshcd_err_handling_should_stop(hba)) {
@@ -6684,14 +6698,6 @@ static void ufshcd_err_handler(struct work_struct *work)
 	}
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
-	ufshcd_rpm_get_noresume(hba);
-	if (hba->pm_op_in_progress) {
-		ufshcd_link_recovery(hba);
-		ufshcd_rpm_put(hba);
-		return;
-	}
-	ufshcd_rpm_put(hba);
-
 	ufshcd_err_handling_prepare(hba);
 
 	spin_lock_irqsave(hba->host->host_lock, flags);