1857d7d776
[ Upstream commit 05d18ae1cc8a0308b12f37b4ab94afce3535fac9 ] 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 a sdev's RPM status was RPM_SUSPENDED. (struct request_queue)0xFFFFFF815B69E938 pm_only = (counter = 2), rpm_status = 0, dev = 0xFFFFFF815B0511A0, ((struct device)0xFFFFFF815B0511A0)).power is_suspended = FALSE, runtime_status = RPM_ACTIVE, (struct scsi_device)0xffffff815b051000 request_queue = 0xFFFFFF815B69E938, sdev_state = SDEV_RUNNING, quiesced_by = 0x0, B::v.f_/task_0xFFFFFF810C246940 -000|__switch_to(prev = 0xFFFFFF810C246940, next = 0xFFFFFF80A49357C0) -001|context_switch(inline) -001|__schedule(?) -002|schedule() -003|blk_queue_enter(q = 0xFFFFFF815B69E938, flags = 0) -004|generic_make_request(?) -005|submit_bio(bio = 0xFFFFFF80A8195B80) Link: https://lore.kernel.org/r/1588740936-28846-1-git-send-email-cang@codeaurora.org Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Can Guo <cang@codeaurora.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.