From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: PandaBoard ES Audio Problems Date: Thu, 31 Jan 2013 20:44:25 +0100 Message-ID: <510AC999.2090205@ladisch.de> References: <510AA9A0.4060009@ladisch.de> <1359656599.10392.13.camel@loki> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) by alsa0.perex.cz (Postfix) with ESMTP id 22FB7264EFF for ; Thu, 31 Jan 2013 20:45:38 +0100 (CET) In-Reply-To: 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: Brent Weatherall Cc: Liam Girdwood , Peter Ujfalusi , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Brent Weatherall wrote: > stepping through the ALSA code, it seems the error *might* be in > the ALSA code, but I am probably reading the code incorrectly: > > pcm/interval.c: That code is correct (it's used in a different context). The problem is that the kernel driver returns wrong min/max values. > Liam Girdwood wrote: >> The OMAP4 ABE driver doesn't actually know the exact constraints if >> there is not a valid playback path between source PCM and sink (it will >> still throw out anything insane though). This is because it can route >> audio from most of it's PCMs to most of it's components, e.g. HS, HF, >> BT, MODEM, Earpiece, etc where some components have different >> constraints. It's possible that you dont have a path in your case. In theory, what the driver should do is: - don't allow the PCM device to be opened if there is no valid route configuration (or just never allow a completely invalid configuration); and - while the PCM device is open, lock the route configuration, or - if changing the route during playback is necessary, allow to set only those routes that are possible with the current PCM configuration. Regards, Clemens