From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: [RFC] disabling ALSA period interrupts Date: Fri, 30 Apr 2010 13:24:13 +0200 Message-ID: <4BDABDDD.4050502@ladisch.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out3.smtp.messagingengine.com (out3.smtp.messagingengine.com [66.111.4.27]) by alsa0.perex.cz (Postfix) with ESMTP id 77C1624347 for ; Fri, 30 Apr 2010 13:24:15 +0200 (CEST) In-Reply-To: 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: pl bossart Cc: General PulseAudio Discussion , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org pl bossart wrote: > When PulseAudio is used and all PCM is routed through PulseAudio > (Fedora, Meego, etc), the notion of ALSA periods isn't very useful. > So why not disable them entirely to reduce the number of wakeups? ... > There are probably some cases where you don't want this type of > behavior (broken hardware, legacy code with multiple-buffering, > disabled timer in PulseAudio), It's interesting that all ALSA applications except PA are "legacy". :) > so I think it would make sense to request the disabling of interrupts > when hw_params are set, since this is also the time when period sizes > are set. Yes. For compatibility with the existing ALSA API, this needs to be a flag that is not enabled by default. > I am aware that some changes would be needed in pcm_lib.c, where all > the error checks are done. Plus all the API changes in the ALSA kernel framework, the ALSA kernel/ userspace interface, and the alsa-lib interface. I'll see if I can get this done over the weekend ... Regards, Clemens