From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758152Ab0EMJhe (ORCPT ); Thu, 13 May 2010 05:37:34 -0400 Received: from buzzloop.caiaq.de ([212.112.241.133]:53673 "EHLO buzzloop.caiaq.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758098Ab0EMJh3 (ORCPT ); Thu, 13 May 2010 05:37:29 -0400 Date: Thu, 13 May 2010 11:36:55 +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: <20100513093655.GG30801@buzzloop.caiaq.de> References: <20100512003450P.fujita.tomonori@lab.ntt.co.jp> <20100511171025.GB30801@buzzloop.caiaq.de> <20100511173830.GF30801@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 Thu, May 13, 2010 at 12:50:48AM +0100, Pedro Ribeiro wrote: > On 11 May 2010 18:38, Daniel Mack wrote: > > 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. > > Ok let me see if I got this straight: > > I should record some sound with the audio card and see if it impacts > the recording? May take me a few days, I need to get a microphone or > something like that borrowed. Yes, exactly. > > 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?). > > > > What do you mean by this? I didn't get it. I usually use my onboard > intel HDA for listening to music and have no problems. I was just thinking of a way to judge whether the recording is affected. And probably the best way is to listen to it :) Daniel