On Thu, Aug 30, 2012 at 10:24:39AM -0400, Alan Stern wrote: > On Thu, 30 Aug 2012, Aaron Lu wrote: > > > Add a new flag may_power_off for scsi device, it gives the user a chance > > to control when the device is runtime suspended, can we remove its power > > if possible. > > > > I'm planning using this flag for sr and sd. > > > > For sr, if user set 0 to may_power_off, we will disable runtime suspend > > for ODD, since runtime suspend for ODD is wholly for zero power ODD, if > > we can't power off the ODD, there is no meaning to do runtime PM on it. > > This doesn't seem like a good idea. Even though you may not be able to > reduce the drive's power usage, you can still allow the runtime_suspend > routine to succeed. This will tell the kernel to consider the drive as > being in a suspended (and therefore unusable) state, allowing the > kernel to do a runtime suspend of the SCSI host that the drive is > attached to. Thanks Alan, I agree that this doesn't quite follow the meaning of may_power_off. I tried to seperate runtime pm with runtime power off in v5 patch of ZPODD, please take a look to see if I did it the right way. Thanks, Aaron -- 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
