Damien Le Moal <dlemoal@xxxxxxxxxx> writes: > system suspend/resume operations, the ATA port used to connect the > device will also be suspended and resumed, with the resume operation > requiring re-validating the device link and the device itself. In this > case, issuing a VERIFY command to spinup the disk must be done before > starting to revalidate the device, when the ata port is being resumed. > In such case, we must not allow the SCSI disk driver to issue START STOP > UNIT commands. Why must a VERIFY be issued to spinup the disk before revalidating? Before these patches, by default, manage_start_stop was on, and so sd would cause a VERIFY in the system resume path. That resume however ( sd and its issuing START UNIT ), would have happened AFTER the link was resumed and the ATA device was revalidated, woudldn't it? So at that point, the drive would already be spinning. And if manage_start_stop was disabled, then there would be no VERIFY at all, and this did not seem to cause a problem before. If this VERIFY were skipped, the next thing that would happen is for ata_dev_revalidate() to issue IDENTIFY, which would wait for the drive to spin up before returning wouldn't it? ( unless the drive has PuiS enabled ).
