2012/11/30 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>: > On Fri, 30 Nov 2012, Lan Tianyu wrote: > >> On 2012年11月29日 01:44, Alan Stern wrote: >> > On Sat, 17 Nov 2012, Lan Tianyu wrote: >> > >> >> This patch is to expose usb port's pm qos flags(pm_qos_no_power_off, >> >> pm_qos_remote_wakeup) to user space. User can set pm_qos_no_power_off >> >> flag to prohibit the port from being power off. >> > >> > Do we really need this? The user already can prevent the port from >> > being powered off by writing "on" to the power/control attribute. >> > >> Hi Alan: >> First, I think your suggestion could work. But I still have some concerns. >> (1) power/control is to control runtime pm rather than power off, this >> maybe confuse user space to use it to prevent power off. PM qos would be >> more generic and friendly since it is dedicated to power off control. > > Well, power-off is a form of power management, so preventing power-off > by preventing runtime PM makes sense. > >> (2) Some other buses(e.g SATA, PCI and etc) would also use PM qos to >> control power off, too. So, I think we should keep consistency to be >> convenient for user space to control. Keep using one same attribute to >> control all kinds of devices. > > This second point is a very good one. You should include it in the > patch description. So you agree to continue to using PM qos in this patchset, right? > > Alan Stern > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
