From mboxrd@z Thu Jan 1 00:00:00 1970 From: Howard Mitchell Subject: Re: pcm512x driver: Mixer control naming issue Date: Sun, 15 Mar 2015 22:28:01 +0000 Message-ID: <55060771.7060200@hmbedded.co.uk> References: <5500DE5B.2020401@hmbedded.co.uk> <5502DAE1.30609@hmbedded.co.uk> <20150313182729.GE28806@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from avasout02.plus.net (avasout02.plus.net [212.159.14.17]) by alsa0.perex.cz (Postfix) with ESMTP id E24DB26046A for ; Sun, 15 Mar 2015 23:28:03 +0100 (CET) In-Reply-To: <20150313182729.GE28806@sirena.org.uk> 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: Mark Brown Cc: Takashi Iwai , alsa-devel@alsa-project.org, Gordon Garrity List-Id: alsa-devel@alsa-project.org On 13/03/15 18:27, Mark Brown wrote: > On Fri, Mar 13, 2015 at 12:41:05PM +0000, Howard Mitchell wrote: > >> Boost Volume) provides a boost of +0.8dB. The hardware reset value of both >> of these gain controls is 0dB, however, in the Raspbian distribution >> 'Playback Volume' is being defaulted to -6dB. >> * Either change the names of these controls to something that's not >> affected by the alsa restore mechanism, > You say "these controls" but it seems like only "Playback Volume" has > a problem? My first suggestion would be to define "Analog" or > "Analogue" as a prefix in ControlNames and then use that, that would > avoid confusing applications while still fittig in with the naming > convention. Yes you are correct that it's only "Playback Volume" that is causing a problem. However, I included "Playback Boost Volume" as it also provides a selection of analogue gain so I think it should be treated similarly for consistency. Defining a new prefix sounds like a reasonable idea in principle but calling it "Analog(ue)" seems like it's saying this is a proper analogue volume control whereas these particular controls merely provide very limited selections of gain. I could imagine that at some point in the future a default for "Analogue Playback Volume" may well be added to "alsactl restore" and then we end up back in the same situation. How about defining a prefix that is documented as saying that a default should not be used if there's nothing in asound.state for that control? >> * or remove them as mixer controls, but make them accessible some >> other way - e.g. device tree. > It may not be policy that someone wants to tweak at runtime on your > board but it almost certainly will be on someone's board. > Fair enough, if that's the general alsa ethos I'm happy to go along with it.