From mboxrd@z Thu Jan 1 00:00:00 1970 From: lokowich Subject: MPC5200 I2S driver for ASoC Date: Wed, 01 Aug 2007 12:33:34 -0500 Message-ID: <46B0C3EE.5020401@acdstar.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sentry.acdstar.com (mail.acdstar.com [209.98.244.9]) by alsa0.perex.cz (Postfix) with ESMTP id 59E1C10384D for ; Wed, 1 Aug 2007 19:46:09 +0200 (CEST) Received: from MailerDaemon by sentry.acdstar.com with local-bsmtp (Exim 4.63) (envelope-from ) id 1IGIGm-0001Bz-FT for alsa-devel@alsa-project.org; Wed, 01 Aug 2007 12:46:00 -0500 Received: from [192.168.2.3] (port=48007 helo=mail.acdstar.com) by sentry.acdstar.com with esmtp (Exim 4.63) (envelope-from ) id 1IGIGk-0001Bu-Bs for alsa-devel@alsa-project.org; Wed, 01 Aug 2007 12:45:58 -0500 Received: from [192.168.2.105] (rnd-03.int.acdstar.com [192.168.2.105]) by mail.acdstar.com (8.13.6/8.13.6) with ESMTP id l71HjoGF009893 for ; Wed, 1 Aug 2007 12:45:50 -0500 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: ALSA-devel List-Id: alsa-devel@alsa-project.org I'm integrating a ALSA driver for an MPC5200 into the ASoC layer, similar to my successful effort for a PXA255 board. I'm modeling the DMA and ALSA interfaces per ac97mgt driver found in the Lite5200B BSP, rather than the BestComm API example in the 2.4 kernel. The speaker-test with 400Hz sine wave is working, but has a slight audible jitter. A wav file output using aplay produces white noise. Debugging shows I get two requests for buffer pointer per service of my transmit ISR (after the single call to snd_pcm_period_elapsed). I expect only one pointer request per interrupt. Could this be the noise problem? This email was Anti Virus checked by Astaro Security Gateway. http://www.astaro.com