From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: UCM representation questions Date: Fri, 27 May 2011 09:31:59 +0800 Message-ID: <20110527013153.GA21016@opensource.wolfsonmicro.com> References: <74CDBE0F657A3D45AFBB94109FB122FF0498A47E52@HQMAIL01.nvidia.com> <4DD7E644.4010301@ti.com> <74CDBE0F657A3D45AFBB94109FB122FF0498A485B6@HQMAIL01.nvidia.com> <4DDE3333.5010907@ti.com> <74CDBE0F657A3D45AFBB94109FB122FF0498A486ED@HQMAIL01.nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource2.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id 1F1F1103A7C for ; Fri, 27 May 2011 03:32:05 +0200 (CEST) Content-Disposition: inline In-Reply-To: <74CDBE0F657A3D45AFBB94109FB122FF0498A486ED@HQMAIL01.nvidia.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: Stephen Warren Cc: "alsa-devel@alsa-project.org" , Liam Girdwood List-Id: alsa-devel@alsa-project.org On Thu, May 26, 2011 at 10:13:21AM -0700, Stephen Warren wrote: > My thought process here was that conflicting devices are probably less > common than non-conflicting devices. At least, it seems like that'd be > the default assumption of someone writing a UCM file. So, if we list > ConflictingDevice(s), then that would often map to an empty list, and > you could eliminate the section. If we had to list all compatible > devices, by default you'd have to list every device in the UCM verb in > almost all cases. That seems like more work. > Plus, adding an optional ConflictingDevice list maintains backwards > Compatibility with any existing UCM files, whereas adding a mandatory > SupportedDevice list doesn't. I tend to agree with this - the usual case is that you can have as many devices as you like running, the reason for restricting things is more normally usefulness rather than physical possibility. > I wonder if allowing all lists of devices to be either inclusive > SupportedDevice or exclusive ConflictingDevice makes sense, with the > default being ConflictingDevice being empty, and SupportedDevice being > the entire set of devices? Seems more complex, but probably still > workable. That makes sense too - if either directive is used we require an explicit list, otherwise we assume everything is compatible.