From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH 1/4] Revert "ASoC: tlv320dac33: Use core to set the msbits constraint" Date: Thu, 19 Jan 2012 19:07:01 +0000 Message-ID: <20120119190701.GN3178@opensource.wolfsonmicro.com> References: <1326997456-16296-1-git-send-email-peter.ujfalusi@ti.com> <1326997456-16296-2-git-send-email-peter.ujfalusi@ti.com> <20120119182602.GM3178@opensource.wolfsonmicro.com> <4F1861E6.1000700@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id 866F82436F for ; Thu, 19 Jan 2012 20:07:04 +0100 (CET) Content-Disposition: inline In-Reply-To: <4F1861E6.1000700@ti.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: Peter Ujfalusi Cc: alsa-devel@alsa-project.org, Liam Girdwood List-Id: alsa-devel@alsa-project.org On Thu, Jan 19, 2012 at 07:33:10PM +0100, Peter Ujfalusi wrote: > It might not bother you that we are wasting CPU cycles for nothing, but > it annoys me. > This is the reason we need to update the CPUs every 2 years. > Please take this series. I'm not going to allow that the TI drivers will > waste CPU cycles (for nothing). Please take a step back (I know I'm rather annoyed and am trying to do so myself), none of this is getting us anywhere. We've got real CPU consumption problems in ASoC - the DAPM algorithm is the biggest one, even with the work I did recently to mitigate against it it's still got the ability to explode dramatically to the point where it's user visible as the worst case is well over O(n^2). There's plenty of low hanging fruit that it'd be much better to spend time on here - as a quick example every time we start or stop a stream we do a linear search of all DAPM widgets looking for those that might be affected based on a string match in order to kick DAPM for them. That's O(n) in the number of widgets in the card plus the strcmp() costs. We'll all get *much* more benefit from working on improvements of things like that (and on the memory consumption which isn't great either and probably manages to burn measurable CPU cycles due to cache misses) than we ever will from anything we do with this code.