usb: hub: Allow reset retry for USB2 devices on connect bounce
authorMathias Nyman <mathias.nyman@linux.intel.com>
Tue, 17 Oct 2017 13:07:33 +0000 (16:07 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 27 Oct 2017 08:38:06 +0000 (10:38 +0200)
commitd15fc53296a529026126568916abca3af9167677
treeaf81da05af5ff5d84ec6d8f0197dcff4288bd318
parentddf0b44fbcb20d63fcddd7cbf6f314a9fabd53ab
usb: hub: Allow reset retry for USB2 devices on connect bounce

commit 1ac7db63333db1eeff901bfd6bbcd502b4634fa4 upstream.

If the connect status change is set during reset signaling, but
the status remains connected just retry port reset.

This solves an issue with connecting a 90W HP Thunderbolt 3 dock
with a Lenovo Carbon x1 (5th generation) which causes a 30min loop
of a high speed device being re-discovererd before usb ports starts
working.

[...]
[ 389.023845] usb 3-1: new high-speed USB device number 55 using xhci_hcd
[ 389.491841] usb 3-1: new high-speed USB device number 56 using xhci_hcd
[ 389.959928] usb 3-1: new high-speed USB device number 57 using xhci_hcd
[...]

This is caused by a high speed device that doesn't successfully go to the
enabled state after the second port reset. Instead the connection bounces
(connected, with connect status change), bailing out completely from
enumeration just to restart from scratch.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1716332
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hub.c