From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932309AbdL1RaJ (ORCPT ); Thu, 28 Dec 2017 12:30:09 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:58932 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754360AbdL1ROB (ORCPT ); Thu, 28 Dec 2017 12:14:01 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Alan Stern" , "Greg Kroah-Hartman" , "Mathias Nyman" Date: Thu, 28 Dec 2017 17:05:44 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 128/204] usb: hub: Allow reset retry for USB2 devices on connect bounce In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Nyman 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 Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/usb/core/hub.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2625,13 +2625,16 @@ static int hub_port_wait_reset(struct us if (!(portstatus & USB_PORT_STAT_CONNECTION)) return -ENOTCONN; - /* bomb out completely if the connection bounced. A USB 3.0 - * connection may bounce if multiple warm resets were issued, + /* Retry if connect change is set but status is still connected. + * A USB 3.0 connection may bounce if multiple warm resets were issued, * but the device may have successfully re-connected. Ignore it. */ if (!hub_is_superspeed(hub->hdev) && - (portchange & USB_PORT_STAT_C_CONNECTION)) - return -ENOTCONN; + (portchange & USB_PORT_STAT_C_CONNECTION)) { + usb_clear_port_feature(hub->hdev, port1, + USB_PORT_FEAT_C_CONNECTION); + return -EAGAIN; + } if (!(portstatus & USB_PORT_STAT_ENABLE)) return -EBUSY;