> -----Original Message----- > From: Sarah Sharp [mailto:sarah.a.sharp@xxxxxxxxxxxxxxx] > Sent: Thursday, September 08, 2011 11:15 PM > To: Xu, Andiry > Cc: gregkh@xxxxxxx; linux-usb@xxxxxxxxxxxxxxx; stern@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH 9/9 v3] usbcore: add sysfs support to xHCI usb2 > hardware LPM > > On Wed, Sep 07, 2011 at 02:04:00PM +0800, Andiry Xu wrote: > > On Tue, 2011-09-06 at 08:18 -0700, Sarah Sharp wrote: > > > On Tue, Sep 06, 2011 at 03:51:47PM +0800, Andiry Xu wrote: > > > > This patch adds sysfs support to xHCI usb2 hardware LPM, so user can > enable > > > > and disable usb2 hardware LPM manually. > > > > > > Will the user have to enable LPM for every device through this sysfs > > > file, or is it enabled by default? It's going to take time to get the > > > Linux distros to backport these patches, and even longer to get them to > > > create udev rules to turn LPM on. > > > > > > > It's enabled by default if LPM test passed. Just provide an interface to > > user to allow them to put it on/off. > > Ok. In that case, I think the sysfs files are really only useful for > kernel developers to measure power consumption with and without LPM. By > the time the file appears to userspace, the xHCI driver will have > already enabled LPM, which sort of defeats the purpose of allowing > userspace to turn it off. > > I still think you should leave the sysfs files in for power consumption > testing, but I doubt they will be useful for userspace to turn LPM off. > OK. I'll specify it's for test purpose. Thanks, Andiry -- 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
