From mboxrd@z Thu Jan 1 00:00:00 1970 From: Troy Kisky Subject: Re: [PATCH 1/3] ASoC: DaVinci: i2s, reduce underruns by combining into 1 element Date: Tue, 01 Sep 2009 14:34:17 -0700 Message-ID: <4A9D9359.7010107@boundarydevices.com> References: <1251761505-11353-1-git-send-email-troy.kisky@boundarydevices.com> <20090901105302.GD18651@sirena.org.uk> <4A9D669F.6090906@boundarydevices.com> <20090901190327.GA25706@opensource.wolfsonmicro.com> <4A9D73BE.8000901@boundarydevices.com> <20090901202855.GA26626@opensource.wolfsonmicro.com> <4A9D871A.0@boundarydevices.com> <20090901212224.GA27078@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from smtpauth00.csee.onr.siteprotect.com (smtpauth00.csee.onr.siteprotect.com [64.26.60.144]) by alsa0.perex.cz (Postfix) with ESMTP id 11E1524152 for ; Tue, 1 Sep 2009 23:34:26 +0200 (CEST) In-Reply-To: <20090901212224.GA27078@opensource.wolfsonmicro.com> 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: avm@ti.com, davinci-linux-open-source@linux.davincidsp.com, alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Mark Brown wrote: > On Tue, Sep 01, 2009 at 01:42:02PM -0700, Troy Kisky wrote: >> Mark Brown wrote: > >>>> is using the same TC. But sram isn't on by default either. And probably shouldn't >>>> be since the newer chips don't have an underrun problem. > >>> Hrm, that suggests that if it's enabled at all the default should depend >>> on the chip in use? > >> That seems unnecessarily complex to me. As long as platform data can >> specify what you need, you'll eventually get it right. If tracking of >> an object is always wrong because of a channel swap, that is easier >> to notice, and debug, and fix, then if the tracking is only occasionally >> wrong. I'd much rather have a repeatable bug. And most codecs do allow >> you to swap the left and right channels. So, for most people, the fix >> will not be to disable channel combining. > > My thinking was that if the newer chips don't have the underrun issue at > all then it seems like a bad move to enable the workaround for them > since they're currently fine. There should be no intermittent problems > if the underrun issue isn't present. > True, there shouldn't be a problem. However, from a efficiency point of view, it is still better to have the workaround. Fewer memory accesses may free a little bandwidth for other uses. Troy