• Can Guo's avatar
    scsi: pm: Balance pm_only counter of request queue during system resume · 05d18ae1
    Can Guo authored
    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.orgReviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
    Signed-off-by: default avatarCan Guo <cang@codeaurora.org>
    Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
    05d18ae1
scsi_pm.c 8.22 KB