On Mon, 4 Nov 2013, Luke-Jr wrote: > On Monday, November 04, 2013 4:22:04 PM Alan Stern wrote: > > On Mon, 4 Nov 2013, Luke-Jr wrote: > > > Perhaps I phrased that wrong: I suspect this is a hardware issue or > > > firmware bug, triggering bad error handling in Linux. After upgrading to > > > 3.12, Linux indeed survives the hub being plugged in, and the hub is > > > usable, but I still see various errors in dmesg. > > > > What errors? > > [33454.079555] usb 2-1: Parent hub missing LPM exit latency info. Power > management will be impacted. This was fixed by commit 9df89d85b407 (usbcore: set lpm_capable field for LPM capable root hubs). I don't know why that commit never got into the 3.12 kernel. Maybe the description didn't explain clearly that it fixed a bug. In any case, if you want to add that commit to your own kernel, you can find it here: https://git.kernel.org/cgit/linux/kernel/git/gregkh/usb.git/commit?id=9df89d85b407690afa46ddfbccc80bec6869971d > [33454.080514] xhci_hcd 0000:03:00.0: xHCI xhci_drop_endpoint called with > disabled ep ffff88006e5cfd80 That's just a warning, not an error. > [33436.081842] hub 2-1:1.0: USB hub found > [33436.082326] hub 2-1:1.0: 4 ports detected > [33436.284763] hub 2-1:1.0: hub_port_status failed (err = -71) This indicates that your hub had some sort of problem communicating with the computer. > [33436.285139] xhci_hcd 0000:03:00.0: URB transfer length is wrong, xHC issue? > req. len = 4, act. len = 4294967292 That is a genuine bug. At least, the bogus value for the actual len is. The error itself probably arose because of the communication failure above. > [33436.285156] hub 2-1:1.0: hub_port_status failed (err = 0) That also looks rather weird. err = 0 shouldn't indicate a failure. > [33436.285399] hub 2-1:1.0: hub_port_status failed (err = -71) > [33436.285629] hub 2-1:1.0: hub_port_status failed (err = -71) More communication failures. 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
