From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx173.postini.com [74.125.245.173]) by kanga.kvack.org (Postfix) with SMTP id 29CFF6B0036 for ; Thu, 21 Mar 2013 17:52:59 -0400 (EDT) Message-ID: <514B811E.2040209@web.de> Date: Thu, 21 Mar 2013 22:52:30 +0100 From: Soeren Moch MIME-Version: 1.0 Subject: Re: [PATCH] USB: EHCI: fix for leaking isochronous data References: <514B3DBB.3060302@web.de> <20130321173324.GY13280@titan.lakedaemon.net> <201303211910.31473.arnd@arndb.de> In-Reply-To: <201303211910.31473.arnd@arndb.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Arnd Bergmann Cc: Jason Cooper , Alan Stern , USB list , Andrew Lunn , Sebastian Hesselbarth , linux-mm@kvack.org, Kernel development list , linux-arm-kernel@lists.infradead.org, michael@amarulasolutions.com On 21.03.2013 20:10, Arnd Bergmann wrote: > On Thursday 21 March 2013, Jason Cooper wrote: >> On Thu, Mar 21, 2013 at 06:04:59PM +0100, Soeren Moch wrote: > >>> >>> Now I found out what is going on here: >>> >>> In itd_urb_transaction() we allocate 9 iTDs for each URB with >>> number_of_packets == 64 in my case. The iTDs are added to >>> sched->td_list. For a frame-aligned scheduling we need 8 iTDs, the >>> 9th one is released back to the front of the streams free_list in >>> iso_sched_free(). This iTD was cleared after allocation and has a >>> frame number of 0 now. So for each allocation when now_frame == 0 we >>> allocate from the dma_pool, not from the free_list. The attached >>> patch invalidates the frame number in each iTD before it is sent to >>> the scheduler. This fixes the problem without the need to iterate >>> over a iTD list. >>> >>> Signed-off-by: Soeren Moch >> >> Wow! Great work Soeren! Talk about a long road to a small fix. Thanks >> for keeping after it. > > +1 > > I hardly understand half of the description above, but that much sounds > plausible. Is this a bug fix that should get backported to stable kernels? > > Arnd > I think this patch should go to stable kernels, too. But I'm not an expert here... Soeren -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org