On Thu, 16 Jan 2014, Phillip Susi wrote: > On 1/16/2014 11:59 AM, Alan Stern wrote: > > Since the START-STOP and TEST UNIT READY (or REQUEST SENSE or > > whatever) commands are likely to take a long time, they should all > > be carried out asynchronously with respect to the resume procedure. > > I don't know what the best way is to implement this. But it is > > important to guarantee that in the RPM_ACTIVE case, the START-STOP > > command gets sent to the disk before any other commands. (This > > isn't an issue in the RPM_SUSPENDED case, as the block layer will > > prevent requests being sent out unless they have the REQ_PM flag > > set.) > > We could avoid that problem by having the resume_early issue the start > command any time it leaves it in RPM_ACTIVE. I don't see any advantage over issuing the start command in the resume callback. Basically, the only difference between resume_early and resume is that runtime PM is disabled during resume_early. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
