Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933427AbcDKNt0 (ORCPT ); Mon, 11 Apr 2016 09:49:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:37414 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932424AbcDKNYB (ORCPT ); Mon, 11 Apr 2016 09:24:01 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Oliver Neukum , Jiri Slaby Subject: [PATCH 3.12 45/98] usb: retry reset if a device times out Date: Mon, 11 Apr 2016 15:22:47 +0200 Message-Id: X-Mailer: git-send-email 2.8.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1492 Lines: 45 From: Oliver Neukum 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- 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 fdcf290a7bc3..066e9af4d4db 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4202,7 +4202,13 @@ 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 = -- 2.8.1