On Wed, 15 Feb 2012, Elric Fu wrote: > Hi all, > > I found a usb 3.0 hub issue. Now I use a NEC xHCI host card and a VIA VL810 3.0 > hub to test suspend/resume function. I found the device attached to a usb 3.0 > hub port didn't respond the address device command in the procedure of > re-enumeration after resume. I tested linux kernel from 2.6.39 to 3.1.0+. All > of them have the issue. > Then I found the root cause by USB CATC. USB core sends a set hub > depth request to > usb 3.0 hub in hub_configure() in superspeed hub initialization. And > If we do a s3/s4, > after resume usb core should reset the device and send the set hub > depth request > again. But before re-enumeration the usb core doesn't do it. So I > added a set hub depth > request after setting configuration in usb_reset_and_verify_device(). > Now it seems like > the issue is gone. Assuming this is the right thing to do, the place to do it is in hub_activate(), not usb_reset_and_verify_device(). 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
