Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754079AbZJUPHs (ORCPT ); Wed, 21 Oct 2009 11:07:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753730AbZJUPHr (ORCPT ); Wed, 21 Oct 2009 11:07:47 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:34494 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751190AbZJUPHr (ORCPT ); Wed, 21 Oct 2009 11:07:47 -0400 Date: Wed, 21 Oct 2009 11:07:51 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: =?UTF-8?B?T3phbiDDh2HEn2xheWFu?= cc: linux-media@vger.kernel.org, linux-kernel , USB list Subject: Re: uvcvideo causes ehci_hcd to halt In-Reply-To: <4ADEC4C5.8010707@pardus.org.tr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1725 Lines: 46 On Wed, 21 Oct 2009, [UTF-8] Ozan Çağlayan wrote: > Nope it didn't help. Here's the DEBUG enabled dmesg output: ... > [ 420.737748] usb 1-5: link qh1024-0001/f6ffe280 start 1 [1/0 us] The periodic schedule was enabled here. > [ 420.737891] usb 1-5: unlink qh1024-0001/f6ffe280 start 1 [1/0 us] And it was disabled here. Do you have any idea why the uvcvideo driver submits an interrupt URB and then cancels it 150 us later? The same thing shows up in the usbmon traces. > [ 420.741605] usb 1-5:1.0: uevent > [ 420.741957] usb 1-5: uevent > [ 420.745592] usb 1-5:1.0: uevent > [ 420.807880] ehci_hcd 0000:00:1d.7: reused qh f6ffe280 schedule > [ 420.807894] usb 1-5: link qh1024-0001/f6ffe280 start 1 [1/0 us] Now ehci-hcd tried to re-enable the periodic schedule. Note that this is 70 ms after it was supposed to be disabled. > [ 420.808780] ehci_hcd 0000:00:1d.7: force halt; handhake f7c6a024 > 00004000 00000000 -> -110 This error message means that the disable request from 70 ms earlier hasn't taken effect. It looks like a nasty hardware bug -- the controller is supposed to disable the schedule no more than 2 ms after being told to do so. Has this device ever worked with any earlier kernels? A little more debugging information could confirm this. After the error occurs, go into /sys/kernel/debug/usb/ehci/0000:00:1d.7 and post a copy of the "registers" file. If there's anything of interest in the other files, post them too. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/