From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755275Ab0DISJv (ORCPT ); Fri, 9 Apr 2010 14:09:51 -0400 Received: from buzzloop.caiaq.de ([212.112.241.133]:58009 "EHLO buzzloop.caiaq.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753359Ab0DISJr (ORCPT ); Fri, 9 Apr 2010 14:09:47 -0400 Date: Fri, 9 Apr 2010 20:09:42 +0200 From: Daniel Mack To: Alan Stern Cc: Pedro Ribeiro , Robert Hancock , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, Greg KH , alsa-devel@alsa-project.org, linux-usb@vger.kernel.org Subject: Re: USB transfer_buffer allocations on 64bit systems Message-ID: <20100409180942.GK30801@buzzloop.caiaq.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 09, 2010 at 12:01:27PM -0400, Alan Stern wrote: > On Fri, 9 Apr 2010, Pedro Ribeiro wrote: > > here is the output of the patch you sent me when the interference is triggered. > > > > The log is long, 1.3mb in size. > > I don't see anything suspicious. The transfer_buffer addresses repeat > every 32 URBs, and the DMA addresses cycle almost entirely uniformly > from 0x20000000 to 0x23ffffff in units of 0x2000 (there are a few gaps > where the interval is a little bigger). The DMA pointers do indeed look sane. I wanted to take a deeper look at this and set up a 64bit system today. However, I fail to see the problem here. Pedro, how much RAM does your machine have installed? Daniel