4.18-stable review patch. If anyone has any objections, please let me know.
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From: Ming Lei ming.lei@redhat.com
commit b233f127042dba991229e3882c6217c80492f6ef upstream.
Runtime PM isn't ready for blk-mq yet, and commit 765e40b675a9 ("block: disable runtime-pm for blk-mq") tried to disable it. Unfortunately, it can't take effect in that way since user space still can switch it on via 'echo auto > /sys/block/sdN/device/power/control'.
This patch disables runtime-pm for blk-mq really by pm_runtime_disable() and fixes all kinds of PM related kernel crash.
Cc: Tomas Janousek tomi@nomi.cz Cc: Przemek Socha soprwa@gmail.com Cc: Alan Stern stern@rowland.harvard.edu Cc: stable@vger.kernel.org Reviewed-by: Bart Van Assche bart.vanassche@wdc.com Reviewed-by: Christoph Hellwig hch@lst.de Tested-by: Patrick Steinhardt ps@pks.im Signed-off-by: Ming Lei ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- block/blk-core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/block/blk-core.c +++ b/block/blk-core.c @@ -3764,9 +3764,11 @@ 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) + /* Don't enable runtime PM for blk-mq until it is ready */ + if (q->mq_ops) { + pm_runtime_disable(dev); return; + }
q->dev = dev; q->rpm_status = RPM_ACTIVE;