From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Mack Subject: Re: USB transfer_buffer allocations on 64bit systems Date: Fri, 9 Apr 2010 20:09:42 +0200 Message-ID: <20100409180942.GK30801@buzzloop.caiaq.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: alsa-devel@alsa-project.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