From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751861AbcFEKVW (ORCPT ); Sun, 5 Jun 2016 06:21:22 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:21642 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799AbcFEKVT (ORCPT ); Sun, 5 Jun 2016 06:21:19 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oliver Neukum , Greg Kroah-Hartman , Willy Tarreau Subject: [PATCH 3.10 017/143] usb: retry reset if a device times out Date: Sun, 5 Jun 2016 12:18:40 +0200 Message-Id: <1465122046-9645-18-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1465122046-9645-1-git-send-email-w@1wt.eu> References: <1465122046-9645-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oliver Neukum commit 264904ccc33c604d4b3141bbd33808152dfac45b upstream. Some devices I got show an inability to operate right after power on if they are already connected. They are beyond recovery if the descriptors are requested multiple times. So in case of a timeout we rather bail early and reset again. But it must be done only on the first loop lest we get into a reset/time out spiral that can be overcome with a retry. This patch is a rework of a patch that fell through the cracks. http://www.spinics.net/lists/linux-usb/msg103263.html Signed-off-by: Oliver Neukum CC: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- drivers/usb/core/hub.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 92873f2..8eb2de6 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4167,7 +4167,13 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1, r = -EPROTO; break; } - if (r == 0) + /* + * Some devices time out if they are powered on + * when already connected. They need a second + * reset. But only on the first attempt, + * lest we get into a time out/reset loop + */ + if (r == 0 || (r == -ETIMEDOUT && j == 0)) break; } udev->descriptor.bMaxPacketSize0 = -- 2.8.0.rc2.1.gbe9624a