From: Christoph Hellwig <hch@lst.de>
Date: Fri, 21 Jul 2017 13:46:10 +0200
Subject: [PATCH] block: disable runtime-pm for blk-mq
References: bnc#1060662
Patch-mainline: v4.12.6
Git-commit: 765e40b675a9566459ddcb8358ad16f3b8344bbe

commit 765e40b675a9566459ddcb8358ad16f3b8344bbe upstream.

The blk-mq code lacks support for looking at the rpm_status field, tracking
active requests and the RQF_PM flag.

Due to the default switch to blk-mq for scsi people start to run into
suspend / resume issue due to this fact, so make sure we disable the runtime
PM functionality until it is properly implemented.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 block/blk-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/block/blk-core.c b/block/blk-core.c
index a7421b772d0e..56a7fac71439 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -3307,6 +3307,10 @@ EXPORT_SYMBOL(blk_finish_plug);
  */
 void blk_pm_runtime_init(struct request_queue *q, struct device *dev)
 {
+	/* not support for RQF_PM and ->rpm_status in blk-mq yet */
+	if (q->mq_ops)
+		return;
+
 	q->dev = dev;
 	q->rpm_status = RPM_ACTIVE;
 	pm_runtime_set_autosuspend_delay(q->dev, -1);
-- 
2.14.2