From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 2/6] ASoC/mpc5200: get rid of the appl_ptr tracking nonsense Date: Wed, 11 Nov 2009 12:24:45 -0700 Message-ID: References: <20091107081631.18908.82921.stgit@angua> <20091107083358.18908.10635.stgit@angua> <9e4733910911070451y28073dbeke6ced6246f5a5c24@mail.gmail.com> <20091107201233.GC31789@sirena.org.uk> <9e4733910911110838w6010cf3atcfcd30c85f0764a1@mail.gmail.com> <20091111183753.GA31815@rakim.wolfsonmicro.main> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail-yw0-f190.google.com (mail-yw0-f190.google.com [209.85.211.190]) by alsa0.perex.cz (Postfix) with ESMTP id E6C3524597 for ; Wed, 11 Nov 2009 20:25:06 +0100 (CET) Received: by ywh28 with SMTP id 28so1279289ywh.16 for ; Wed, 11 Nov 2009 11:25:06 -0800 (PST) In-Reply-To: <20091111183753.GA31815@rakim.wolfsonmicro.main> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Mark Brown Cc: John Bonesio , alsa-devel@alsa-project.org, linuxppc-dev@lists.ozlabs.org, lrg@slimlogic.co.uk List-Id: alsa-devel@alsa-project.org On Wed, Nov 11, 2009 at 11:37 AM, Mark Brown wrote: > On Wed, Nov 11, 2009 at 11:38:06AM -0500, Jon Smirl wrote: >> > Providing a final valid data point to the driver would possibly even >> > make things worse since if it were used then you'd have the equivalent >> > race where the application has initialized some data but not yet manag= ed >> > to update the driver to tell it it's being handed over; if the driver > >> That's an under run condition. > > Yes, of course - the issue is that this approach encourages them, making > the system less robust if things are on the edge. =A0The mpc5200 seems to > be not just on the edge but comfortably beyond it for some reason. I can't reproduce the issue at all as long at the dev_dbg() statement in the trigger stop path is disabled. With it enabled, I hear the problem every time. The 5200 may not be a speedy beast, but it is plenty fast enough to shut down the audio stream before stale data starts getting played out. g. -- = Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.