Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754598AbZJUR0q (ORCPT ); Wed, 21 Oct 2009 13:26:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754532AbZJUR0n (ORCPT ); Wed, 21 Oct 2009 13:26:43 -0400 Received: from perceval.irobotique.be ([92.243.18.41]:45264 "EHLO perceval.irobotique.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754019AbZJUR0m convert rfc822-to-8bit (ORCPT ); Wed, 21 Oct 2009 13:26:42 -0400 From: Laurent Pinchart To: Alan Stern Subject: Re: uvcvideo causes ehci_hcd to halt Date: Wed, 21 Oct 2009 19:27:00 +0200 User-Agent: KMail/1.12.2 (Linux/2.6.31.1; KDE/4.3.2; x86_64; ; ) Cc: Ozan =?utf-8?q?=C3=87a=C4=9Flayan?= , linux-media@vger.kernel.org, "linux-kernel" , USB list References: In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Message-Id: <200910211927.00298.laurent.pinchart@ideasonboard.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1064 Lines: 29 On Wednesday 21 October 2009 17:07:51 Alan Stern wrote: > 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. Probably because hal opens the device to query its capabilities and closes it right after. The driver submits the interrupt URB when the first user opens the device and cancels it when the last user closes the device. -- Regards, Laurent Pinchart -- 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/