Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751398AbcDJTjy (ORCPT ); Sun, 10 Apr 2016 15:39:54 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54718 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933207AbcDJTTE (ORCPT ); Sun, 10 Apr 2016 15:19:04 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oliver Neukum Subject: [PATCH 3.14 13/76] usb: retry reset if a device times out Date: Sun, 10 Apr 2016 11:36:21 -0700 Message-Id: <20160410183516.562835626@linuxfoundation.org> X-Mailer: git-send-email 2.8.0 In-Reply-To: <20160410183516.090999097@linuxfoundation.org> References: <20160410183516.090999097@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1378 Lines: 43 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hub.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4224,7 +4224,13 @@ hub_port_init (struct usb_hub *hub, stru 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 =