“Norbert Feulner” <email@example.com> wrote in message
The first click in the mute-box of the line settings after moving the
volume slider has no effect on the sound output, until I move the
slider again; i.e. moving the slider seems to update the output.
Clicking mute several times: first click is ignored, further clicks
toggle the sound output, but it’s twisted, mute on → output on, mute
off → output off.
Clicking the CD mute box while the CD volume slider is in max.
position (or close to max) toggels the line mute as well. With the
volume slider in min position there is no such effect.
Video and Aux settings: Clicking the mute box moves the corresponding
volume slider to a max position without x-ing the box.
That sounds like there’s problem communicating to mixer, or mixer control
code is not right. The mute/volume is controlled by callbacks supplied by
driver (the AC97 dll does not do it by itself).
- Changing the PCM settings makes a crack in the speaker but there is
no sound output.
Did you try to play with mute/volume while playing digital audio? From what
you’re saying it sounds like output might be just muted improperly.
If volume control does not work for playing audio CD, check if have
sharp spikes of CPU usage (and apparent slowness of system) when you try
to use volume control. If that is the case, I have some idea what is
Did you see such CPU load spikes or not?
Is there anybody out there that has uesed that driver before
successfully or unsuccessfully?
Yes, I use it myself and several other people use it with Maestro-3 chips.
What documentation did you have for develloping?
ALSA-0.5 code. There is no public documentation beyond that.
One likely source of problem might be subchannel mixer implementation. ALSA
does not have that feature, so I had no documentation at all. However, some
QNX applications only work properly when subchannel mixers are provided. I
tried to ‘guess’ how to do it just by looking at registers and it seemed to
work for Maestro-3. It might be quite different story for Allegro since they
have built-in mixers. You might want to experiment, or to disable subchannel
I also downloaded the source of igor’s home page, I managed to translate
and run it, but seems to be hard to locate the problem (maybe it’s in
the AC’97 lib ?? )
It was harder to figure original ALSA code
Take a look at the source, there are #ifdefs with proper manifests to
enable/disable subchannel mixers.