[alsa-devel] Why was the built-in software volume control removed?

[Jaroslav Kysela]

On Thu, 4 Oct 2007, kyle cronan wrote:

> I think I may have posted this to the wrong list.  There wasn't any
> response yet on alsa-user, so I'm reposting here.
> 
> Summary: I'm seeing a lot of glitches ever since the built-in software
> volume was removed.  What was the reason for this change?  Softvol
> doesn't work nearly as well for me.

The changelog refers to PC-Speaker driver not HDA audio driver. I guess, 
you're seeing another problem. Try to determine exact ALSA version where 
your configuration fails (if you can - try to determine exact HG 
(mercurial) revision of the ALSA driver code).

					Thanks,
						Jaroslav

> ________________
> 
> Hi everyone,
> 
> I recently updated my media center which is running Fedora devel.  It
> pulled down a new kernel with updated ALSA drivers for my HDA audio
> chip (Intel 82801H + ALC883).
> 
> I use IEC958 output to a pair of studio monitors (good sound with
> minimal fuss).  The first thing I noticed about the update was that my
> software volume control was no longer saving state.  It was resetting
> to something around 80% every time an app opened the audio device, a
> level which, in my setup, is quite loud!  Then I saw that in alsamixer
> I had no master volume control, not even a PCM control!
> 
> So I started experimented with my settings, and I found that after I
> selected "PCM" under "Default Mixer Tracks" in gnome-sound-properties
> I had a PCM volume control again (still no master), and apps using
> alsa output would once again remember the system volume.  Don't know
> what that gnome setting actually did, but I've not been able to get it
> back to the original state, even when I ctrl-click to deselect "PCM"
> in the list.
> 
> However, apps that use legacy OSS output still blast me with nearly
> full volume every time.  I've also noticed another glitch: using the
> volume control applet to adjust my PCM volume, the audio sometimes
> skips.  If I quickly drag the slider back and forth, it always does.
> I'm pretty sure I would have noticed this if it occurred with my
> previous kernel (haven't had a chance to test that yet).
> 
> Anyway, looking into this problem, I found the following note in the
> changes document at
> http://www.alsa-project.org/main/index.php/Changes_v1.0.15rc2_v1.0.15rc3
> 
> Sound Core
>   ...
>   - Remove the built-in software volume control in favour of softvol.
> 
> So, my (main) question is: is there a good reason that the built-in
> software volume was removed?  I didn't find anything about it in the
> archives for this list or -devel.  I'm really not in favor of this
> change, because It used to work flawlessly for me, whereas now I'm
> running into all these strange problems with my IEC958 output.
> 
> Thanks,
> Kyle Cronan
> <kyle at pbx.org>

-----
Jaroslav Kysela <perex at suse.cz>
Linux Kernel Sound Maintainer
ALSA Project, SUSE Labs