From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Nikula Subject: Re: [RFC][PATCH 2/3] ASoC: OMAP: Make use of DMA channel self linking on OMAP1510 Date: Mon, 17 Aug 2009 12:18:58 +0300 Message-ID: <20090817121858.fe80fb95.jhnikula@gmail.com> References: <200908101050.05314.jkrzyszt@tis.icnet.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ew0-f214.google.com ([209.85.219.214]:60311 "EHLO mail-ew0-f214.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757528AbZHQJR1 (ORCPT ); Mon, 17 Aug 2009 05:17:27 -0400 In-Reply-To: <200908101050.05314.jkrzyszt@tis.icnet.pl> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Janusz Krzysztofik Cc: Mark Brown , Peter Ujfalusi , Tony Lindgren , "alsa-devel@alsa-project.org" , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.arm.linux.org.uk" , "linux-kernel@vger.kernel.org" On Mon, 10 Aug 2009 10:50:04 +0200 Janusz Krzysztofik wrote: > Use newly implemented DMA channel self linking on OMAP1510 like on other OMAP > models. Remove unnecessary DMA transfer restart from interrupt handler > routine. > > The interrupt routine used to maintain a period index, originally needed for > counting up periods up to a full buffer in order to restart the DMA transfer. > For some time, this counter is also used as a replacement for hardware DMA > progress counter that has been found unusable on OMAP1510 in case of playback. > Thus, the period index calculation cannot be omitted completely. However, the > accuracy of this counter can still suffer from missing DMA interrupts. > > In order to work correctly, it requires patch 1 from this series also applied: > [RFC][PATCH 1/3] ARM: OMAP: DMA: Add support for DMA channel self linking on OMAP1510 > > Created against linux-2.6.31-rc5. > > Tested on Amstrad Delta. > > Signed-off-by: Janusz Krzysztofik > Nice to see code to be more uniform across the OMAP's. Note this depends on patch 1 which touches the arch/arm/plat-omap/dma.c. Acked-by: Jarkko Nikula