[PATCH 7.3.y] scsi: ufs: core: Change the error check sequence for auto hibern8

[Sasha Levin <sashal@kernel.org>]

From: HOYOUNG SEO <hy50.seo@samsung.com>

[ Upstream commit 6b2ff2b3eafa381db9b4c8a6ed98b353b2a09f39 ]

Auto-hibern8 enter and exit are performed by the host controller without a
UIC command, and the auto-hibern8 idle timer only runs while no UIC command
is outstanding. An auto-hibern8 error (IS.UHES or IS.UHXS) is therefore
usually reported while hba->active_uic_cmd is NULL.

Since commit fcd8b0450a9a ("scsi: ufs: core: Make ufshcd_uic_cmd_compl()
easier to analyze"), ufshcd_uic_cmd_compl() returns early when
hba->active_uic_cmd is NULL, before ufshcd_is_auto_hibern8_error() is
called. Such auto-hibern8 errors are no longer recorded in hba->errors, so
ufshcd_check_errors() is not called for them and the error handler is not
scheduled.

Check for auto-hibern8 errors before checking for an active UIC command, as
was done before that commit, but keep returning early when there is no
active UIC command so that a NULL cmd is never dereferenced. Only report
the missing UIC command if no auto-hibern8 error was found.

Fixes: fcd8b0450a9a ("scsi: ufs: core: Make ufshcd_uic_cmd_compl() easier to analyze")
Cc: stable@vger.kernel.org # v6.13+
Signed-off-by: HOYOUNG SEO <hy50.seo@samsung.com>
Reviewed-by: Stanley Jhu <stanleyjhu@google.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20261027110357.3649301-1-hy50.seo@samsung.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>
[ sashal: Retained hba->host->host_lock without the address-of operator because host_lock is a pointer. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/ufs/core/ufshcd.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index dfbcf036d356c..490feaeee10b2 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5876,18 +5876,26 @@ static irqreturn_t ufshcd_uic_cmd_compl(struct ufs_hba *hba, u32 intr_status)
 {
 	irqreturn_t retval = IRQ_NONE;
 	struct uic_command *cmd;
+	bool ah8_err;
 
 	guard(spinlock_irqsave)(hba->host->host_lock);
+
+	/*
+	 * Auto-hibern8 is performed without a UIC command, so check for
+	 * auto-hibern8 errors before checking for an active UIC command.
+	 */
+	ah8_err = ufshcd_is_auto_hibern8_error(hba, intr_status);
+	if (ah8_err)
+		hba->errors |= (UFSHCD_UIC_HIBERN8_MASK & intr_status);
+
 	cmd = hba->active_uic_cmd;
 	if (!cmd) {
-		dev_err(hba->dev,
-			"No active UIC command. Maybe a timeout occurred?\n");
+		if (!ah8_err)
+			dev_err(hba->dev,
+				"No active UIC command. Maybe a timeout occurred?\n");
 		return retval;
 	}
 
-	if (ufshcd_is_auto_hibern8_error(hba, intr_status))
-		hba->errors |= (UFSHCD_UIC_HIBERN8_MASK & intr_status);
-
 	if (intr_status & UIC_COMMAND_COMPL) {
 		/*
 		 * Store the UIC command result in the lowest byte of
-- 
2.53.0