From mboxrd@z Thu Jan 1 00:00:00 1970 From: Raymond Yau Subject: Re: Handling of the DXS controls in the via82xx driver Date: Mon, 29 Mar 2010 09:24:33 +0800 Message-ID: <4f3252891003281824r4544d4bfv811f9c4e4d98381@mail.gmail.com> References: <4BAE8EF7.20204@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail-pw0-f51.google.com (mail-pw0-f51.google.com [209.85.160.51]) by alsa0.perex.cz (Postfix) with ESMTP id F1453103806 for ; Mon, 29 Mar 2010 03:24:34 +0200 (CEST) Received: by pwj7 with SMTP id 7so7006618pwj.38 for ; Sun, 28 Mar 2010 18:24:34 -0700 (PDT) In-Reply-To: <4BAE8EF7.20204@gmx.de> 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: ALSA Development Mailing List List-Id: alsa-devel@alsa-project.org 2010/3/28 Soeren D. Schulze > Hi everyone, > > before my latest upgrade to Linux 2.6.32 (yes, sorry, it's Debian), I > had four levers in my alsamixer: VIA DXS, VIA DXS 1, VIA DXS 2 and VIA > DXS 3. They controlled the hardware mixing when accessing the sound > device multiple times. > > Now they have disappeared. I think I can pretty certainly trace this > down to commit 2fb930b53f513cbc4c102d415d2923a8a7091337 to Linux > [ > http://git.kernel.org/?p=3Dlinux/kernel/git/stable/linux-2.6.32.y.git;a= =3Dcommit;h=3D2fb930b53f513cbc4c102d415d2923a8a7091337 > ], > which "move[s] DXS volume controls to PCM interface". > > As I'm not an ALSA developer, I don't realize the intended effect of > this change, but the actual effect is that I cannot change the DXS > volumes any more. mplayer still controls the global PCM volume. Well, > in fact, there is one way. While an mplayer is running, I can do: > > amixer cset numid=3D47,iface=3DPCM,name=3D'PCM Playback Volume' 24,24 > > When restarting mplayer, the volume is reset to 31,31 (maximum). Commit > 3d00941371a765779c4e3509214c7e5793cce1fe > [ > http://git.kernel.org/?p=3Dlinux/kernel/git/stable/linux-2.6.33.y.git;a= =3Dcommit;h=3D3d00941371a765779c4e3509214c7e5793cce1fe > ] > seems to be responsible for this. > > The bad thing about it is that 31,31 is a really bad setting for my > poorly engineered sound card. It distorts a lot. > > I suspect that the real *bug* is that mplayer does not use the > per-channel DXS controls even though it's supposed to (which seems to be > why the DXS controls are called "PCM Playback Volume"). > > Personally, rather than fixing this bug, I would just revert to the > former state. I was always happy with all the DXS levers set to 75%. > > > Thank you > > S=F6ren > Those are per voice volume control , they can be used for the hardware acclearation in wine if wine implmenet the real hardware acceleration After this change , they are not used by the mixer any more , only those application which open those subdevices can find the corresponding control by the subdevice number