Messages in this thread | | | Subject | Re: [PATCH v3 1/1] scsi: pm: Balance pm_only counter of request queue during system resume | From | Bart Van Assche <> | Date | Thu, 30 Apr 2020 18:50:03 -0700 |
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On 2020-04-30 18:42, Can Guo wrote: > On 2020-05-01 04:32, Bart Van Assche wrote: > > Has it been considered to test directly whether a SCSI device has been > > runtime suspended instead of relying on blk_queue_pm_only()? How about > > using pm_runtime_status_suspended() or adding a function in > > block/blk-pm.h that checks whether q->rpm_status == RPM_SUSPENDED? > > Yes, I used to make the patch like that way, and it also worked well, as > both ways are equal actually. I kinda like the current code because we > should be confident that after scsi_dev_type_resume() returns, pm_only > must be 0. Different reviewers may have different opinions, either way > works well anyways.
Hi Can,
Please note that this is not a matter of personal preferences of a reviewer but a matter of correctness. blk_queue_pm_only() does not only return a value > 0 if a SCSI device has been runtime suspended but also returns true if scsi_device_quiesce() was called for another reason. Hence my request to test the "runtime suspended" status directly and not to rely on blk_queue_pm_only().
Thanks,
Bart.
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