For SCSI disks that are runtime suspended, it looks like they skip waking the disk on system resume, leaving them in runtime suspend. After these patches, it looks like libata always wakes up the disk, but I don't see any calls to pm_runtime_disable/set_active/enable to mark the scsi disk as active after the system resume. That should result in a disk that is spinning, but runtime pm thinks is not, and so will not put it into suspend after the inactivity timeout.
