On Tue, Sep 09, 2014 at 07:28:00PM +0200, Oliver Neukum wrote: > On Tue, 2014-09-09 at 12:53 -0400, Alan Stern wrote: > > On Tue, 9 Sep 2014, Oliver Neukum wrote: > > > > > On Tue, 2014-09-09 at 11:23 -0400, Alan Stern wrote: > > > > On Tue, 9 Sep 2014, Oliver Neukum wrote: > > > > > > > > > Hi, > > > > > > > > > > Johan's patch means that for the affected touchscreen the port > > > > > can never be powered off. It seems to me that this needs a special > > > > > flag. What do you think? > > > > > > > > Why can't the port be powered off? > > > > > > needs_remote_wakeup is permanently set. > > > > That's okay, then. We never power-down a port if the attached device > > is enabled for remote wakeup. See the last few lines in > > usb_port_suspend() in hub.c. > > Yes, that is the problem. I need to be more verbose. I am sorry. > These devices have a firmware bug. Actually several, but only one > is relevant here. > > If they are suspended without remote wakeup they crash and > disconnect/reconnect as soon as they have data to deliver. > So we cannot suspend them without remote wakeup. Yet we would > very much like to power them down, for example when the laptop's > lid is closed. > > I think the only way to do that is to tell usbcore to honour > needs_remote_wakeup for suspend but not power off by means > of an additional flag. But this wouldn't just be required with the always-poll quirk as generally the device would have been opened by the Xorg driver and needs_remote_wakeup set anyway. Johan -- 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
