From: Stanley Chu <stanley.chu@mediatek.com>
Date: Thu, 12 Sep 2019 16:35:27 +0800
Subject: [PATCH] block: bypass blk_set_runtime_active for uninitialized q->dev
Git-commit: 8a15b4d7cd872b784f585d38d9240f6ee588381b
Patch-Mainline: v5.4-rc1
References: bsc#1156419,jsc#SLE-8281

Some devices may skip blk_pm_runtime_init() and have null pointer
in its request_queue->dev. For example, SCSI devices of UFS Well-Known
LUNs.

Currently the null pointer is checked by the user of
blk_set_runtime_active(), i.e., scsi_dev_type_resume(). It is better to
check it by blk_set_runtime_active() itself instead of by its users.

Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.de>
---
 block/blk-pm.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/block/blk-pm.c b/block/blk-pm.c
index 0a028c189897..1adc1cd748b4 100644
--- a/block/blk-pm.c
+++ b/block/blk-pm.c
@@ -207,10 +207,12 @@ EXPORT_SYMBOL(blk_post_runtime_resume);
  */
 void blk_set_runtime_active(struct request_queue *q)
 {
-	spin_lock_irq(&q->queue_lock);
-	q->rpm_status = RPM_ACTIVE;
-	pm_runtime_mark_last_busy(q->dev);
-	pm_request_autosuspend(q->dev);
-	spin_unlock_irq(&q->queue_lock);
+	if (q->dev) {
+		spin_lock_irq(&q->queue_lock);
+		q->rpm_status = RPM_ACTIVE;
+		pm_runtime_mark_last_busy(q->dev);
+		pm_request_autosuspend(q->dev);
+		spin_unlock_irq(&q->queue_lock);
+	}
 }
 EXPORT_SYMBOL(blk_set_runtime_active);
-- 
2.16.4