> > On 2020-04-29 21:10, Can Guo wrote: > > 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 pm_only is non-zero to balance the pm_only > > counter which is held by the scsi device's RPM ops. > > How was this issue discovered? How has this patch been tested? I think this insight was originally gained as part of commit fb276f770118 (scsi: ufs: Enable block layer runtime PM for well-known logical units) But I will let Can reply on that. Thanks, Avri > > Thanks, > > Bart.
