block: disable runtime-pm for blk-mq

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>

1 files changed, 4 insertions, 0 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 970b9c9638c5..dbecbf4a64e0 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -3421,6 +3421,10 @@ 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);