On Thursday 06 September 2012 13:08:18 Alan Stern wrote: > On Thu, 6 Sep 2012, Oliver Neukum wrote: > > > On Thursday 06 September 2012 11:06:49 Alan Stern wrote: > > > On Thu, 6 Sep 2012, Aaron Lu wrote: > > > > > > > > That's why we have an autosuspend delay. Although for some reason the > > > > > SCSI subsystem doesn't use it currently... We need to add a call to > > > > > pm_runtime_use_autosuspend() in scsi_sysfs_add_sdev(). Likewise, the > > > > > pm_schedule_suspend() call in scsi_runtime_idle() should be changed to > > > > > pm_runtime_autosuspend(). And there should be calls to > > > > > pm_runtime_set_autosuspend_delay() in the sd and sr drivers. > > > > > > > > I tried to use autosuspend when preparing the patch, but the fact that > > > > the devices will be polled every 2 seconds make it impossible to enter > > > > suspend state if the autosuspend delay is larger than that. > > > > > > You can always increase the polling interval. > > > > > > But in the long run that wouldn't be a good solution. What I'd really > > > like is a way to do the status polling without having it reset the > > > idle timer. > > > > > > Oliver, what do you think? Would that be a good solution? > > > > Well, we could introduce a flag into the requests for the polls. > > But best would be to simply declare a device immediately idle > > as soon as we learn that it has no medium. No special casing > > would be needed. > > We could do that, but what about idle drives that do have media? Then we do have a problem. To handle this optimally we'd have to make a difference between the first time a new medium is noticed and later polls. Regards Oliver -- 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
