On Wed, 30 Mar 2011, Xu, Andiry wrote: > > I'm not entirely sure how USB 3.0 hard drives are going to react to > > having their port power turned off. I suppose at that point they'll > > migrate over to the USB 2.0 wires, since they all have external power > > supplies anyway. Then during resume, we would have to re-enable port > > power for those ports when the USB 3.0 roothub is resumed. Since the > > USB 3.0 roothub should be resumed before any devices are reset on the > > USB 2.0 roothub, I think this will work, but I'm skeptical that it's > > going to be a smaller patchset that the current one Andiry created. > > > > I've done some basic tests. Clear PORT_POWER during suspend and the > system can suspend/resume normally, but after system resume, the USB3.0 > device disappears. Simply set PORT_POWER does not help. The port link > state is Inactive and I think a warm reset is needed. If you just want > the system suspend/resume succeed, it's enough, but to make the device > resume normally, more investigation is needed. Or do I miss something? I think that alone would be good enough for now. 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
