From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Dominic_Sacr=c3=a9?= Subject: snd-fireworks requires larger period sizes than FFADO Date: Sun, 22 Nov 2015 01:20:47 +0100 Message-ID: <56510A5F.4080004@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) by alsa0.perex.cz (Postfix) with ESMTP id 870FC260609 for ; Sun, 22 Nov 2015 01:21:31 +0100 (CET) Received: from [192.168.0.201] ([37.24.103.185]) by mail.gmx.com (mrgmx002) with ESMTPSA (Nemesis) id 0Lck9X-1ajqJA0eX9-00k71R for ; Sun, 22 Nov 2015 01:21:31 +0100 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 Hi, I'm trying to use an Echo AudioFire 4 with the snd-fireworks driver. With FFADO the device works reasonably well at a period size of 64 samples (on a PREEMPT_RT kernel), whereas with snd-fireworks the lowest possible period size seems to be 256 samples. This is what JACK says when I try to start it with a period size of 128 samples: configuring for 48000Hz, period = 128 frames (2.7 ms), buffer = 2 periods ALSA: final selected sample format for capture: 32bit integer little-endian ALSA: cannot set period size to 128 frames for capture The lowest achievable analog roundtrip latency seems to be around 19ms (at 2x256 frames), as opposed to 8.3ms with FFADO (at 2x64). Are there any known limitations of the snd-fireworks driver in this regard? Thanks, Dominic