From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753251Ab0EKRiw (ORCPT ); Tue, 11 May 2010 13:38:52 -0400 Received: from buzzloop.caiaq.de ([212.112.241.133]:37958 "EHLO buzzloop.caiaq.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751056Ab0EKRiu (ORCPT ); Tue, 11 May 2010 13:38:50 -0400 Date: Tue, 11 May 2010 19:38:30 +0200 From: Daniel Mack To: Pedro Ribeiro Cc: Alan Stern , FUJITA Tomonori , gregkh@suse.de, konrad.wilk@oracle.com, tiwai@suse.de, USB list , clemens@ladisch.de, Kernel development list , chrisw@sous-sol.org, iommu@lists.linux-foundation.org, andi@firstfloor.org, Andrew Morton , dwmw2@infradead.org Subject: Re: [alsa-devel] USB transfer_buffer allocations on 64bit systems Message-ID: <20100511173830.GF30801@buzzloop.caiaq.de> References: <20100512003450P.fujita.tomonori@lab.ntt.co.jp> <20100511171025.GB30801@buzzloop.caiaq.de> 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 Tue, May 11, 2010 at 06:32:50PM +0100, Pedro Ribeiro wrote: > On 11 May 2010 18:10, Daniel Mack wrote: > > No surprise here. The 4 channels are mux'ed in an interleaved fashion, > > so if the buffers contain rubbish, you will hear artefacts on all > > channels. > > So what would be the testcase you would like me to try? Would be good to see what happens if you could record audio (with arecord would be sufficient), just to see whether the same problem exists in the other direction. Either record an externally generated sine tone and open the resulting wave file in an editor. With the amount of artefacts you describe, they should easily be visible. Another option is to play back any kind of recorded audio thru an audio device that does not show the problem (some internal, onboard device?). Thanks, Daniel