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. (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. Just from my opinion, look forward to your comment.:) > Alan Stern > -- 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
