From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [92.198.50.35]) by ozlabs.org (Postfix) with ESMTP id CD572DE0C4 for ; Mon, 25 May 2009 17:57:48 +1000 (EST) From: Juergen Beisert To: linuxppc-dev@ozlabs.org Date: Mon, 25 May 2009 09:56:27 +0200 References: <20090523231148.17919.46103.stgit@terra> <20090524185509.GA3561@pengutronix.de> <9e4733910905241310n59952fd2oaafd7f1363db324@mail.gmail.com> In-Reply-To: <9e4733910905241310n59952fd2oaafd7f1363db324@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200905250956.28206.jbe@pengutronix.de> Subject: Re: [PATCH V2 5/9] Main rewite of the mpc5200 audio DMA code Cc: alsa-devel@alsa-project.org, broonie@sirena.org.uk List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Jon, On Sonntag, 24. Mai 2009, Jon Smirl wrote: > On Sun, May 24, 2009 at 2:55 PM, Wolfram Sang wrote: > >> Rewrite the mpc5200 audio DMA code to support both I2S and AC97. Make it > >> more robust. > > > > Why is it more robust? > > I've implemented retries for when the AC97 hardware doesn't reset on > first try. About 10% of the time both the Efika and pcm030 AC97 codecs > don't reset on first try and need to be poked multiple times. Failure > is indicated by not having the link clock start ticking. Every once in > a while even five pokes won't get the link started and I have to power > cycle. Do you know this (from our website)? "The AC97 mixer needs a hardware patch to make it wake up from power down mode. Download here the instruction how to do so." http://www.pengutronix.de/oselas/bsp/phytec/download/phyCORE-MPC5200B-tiny/TN-015e_1.pdf jbe -- Pengutronix e.K. | Juergen Beisert | Linux Solutions for Science and Industry | Phone: +49-8766-939 228 | Vertretung Sued/Muenchen, Germany | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de/ |