From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: ASoC: mmap or read/write? Date: Fri, 19 Oct 2012 10:58:14 +0200 Message-ID: <50811626.9030100@ladisch.de> References: <5080F434.6040602@topic.nl> 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 C39C92625DB for ; Fri, 19 Oct 2012 10:59:31 +0200 (CEST) Received: from compute5.internal (compute5.nyi.mail.srv.osa [10.202.2.45]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id 3D65D20323 for ; Fri, 19 Oct 2012 04:59:31 -0400 (EDT) Received: from [192.168.42.150] (unknown [46.115.34.159]) by mail.messagingengine.com (Postfix) with ESMTPA id AFD0348259C for ; Fri, 19 Oct 2012 04:59:30 -0400 (EDT) In-Reply-To: <5080F434.6040602@topic.nl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Mike Looijmans wrote: > From: Prasant J >>> Prasant J wrote: >>>> I'm writing an alsa application for recording & playing 16 channel audio. >> >> I'm working with Beaglebone (ARM Cortex-A8 720 MHz). (Currently >> failures are for 8 channels 32 bit / 16 bit, but our final target is >> 16 channels) >> >> I have managed to get Audio capture working fine (after certain linux >> optimizations) but playback is giving under-runs (only when PLAYBACK & >> CAPTURE run together) > > You must be doing something wrong. I'm doing 32-bit, 16-channel input > at 51.2kHz on a OMAP-L138 (an ARM9 CPU at 450 MHz) Playback and capture at the same time seems to be harder for certain embedded devices. I don't know if this is a driver bug or a hardware limitation. Regards, Clemens