Commit dc511639 authored Apr 08, 2020 by Can Guo

scsi: pm: Balance pm_only of request queue during system resume

During system resume, scsi_resume_device() decreases a request queue's
pm_only counter if the scsi device was quiesced before. But after that,
if the scsi device's RPM status is RPM_SUSPENDED, the pm_only counter is
still held (non-zero). Current scsi resume hook only sets the RPM status
of the scsi device and its request queue to RPM_ACTIVE, but leaves the
pm_only counter unchanged. This may make the request queue's pm_only
counter remain non-zero after resume hook returns, hence those who are
waiting on the mq_freeze_wq would never be woken up. Fix this by calling
blk_post_runtime_resume() if this sdev's RPM status was RPM_SUSPENDED.

Change-Id: I11736dae2d3e79fc940f97433da89b89e2de9044
Signed-off-by: Can Guo <cang@codeaurora.org>

parent 983f8387

drivers/scsi/scsi_pm.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -80,6 +80,10 @@ static int scsi_dev_type_resume(struct device *dev,
		dev_dbg(dev, "scsi resume: %d\n", err);

		if (err == 0) {
		bool was_runtime_suspended;

		was_runtime_suspended = pm_runtime_suspended(dev);

		pm_runtime_disable(dev);
		err = pm_runtime_set_active(dev);
		pm_runtime_enable(dev);
		@@ -93,7 +97,9 @@ static int scsi_dev_type_resume(struct device *dev,
		*/
		if (!err && scsi_is_sdev_device(dev)) {
		struct scsi_device *sdev = to_scsi_device(dev);

		if (was_runtime_suspended)
		blk_post_runtime_resume(sdev->request_queue, 0);
		else
		blk_set_runtime_active(sdev->request_queue);
		}
		}