[Bug 32394] weird interaction between headphone detect and auto mute on iBook G4 (snapper/tumbler)

[John Steele Scott]

Public bug reported:
https://launchpad.net/malone/bugs/32394

Affects: linux-source-2.6.15 (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
Okay, I'm running 2.6.15-15 on my iBook G4, and the audio is now
generally working. The only bug I notice these days is to do with
headphone detection.

Test setup:
iBook G4 with headphones plugged in, playing music. What I want is for the music to automatically switch to internal speaker when I unplug the headphone. Then, when I plug the headphone in again, it should switch back to playing through the headphones.

What actually happens depends somehow on the setting of Headphone Detect
and Auto Mute, but is not consistent. By default, my system has
Headphone Detect and Auto Mute both set. When I unplug the headphones,
the music switches over to internal speaker, as expected. The DRC switch
becomes set, which is a good thing. But the Headphone Detect switch
becomes unset, which is bad. Then when I plug the headphones back in,
the music does not switch to the headphones, but stays coming out the
internal speaker.

In fact, if I set the Headphone Detect switch manually after unplugging,
this still does not solve the problem. The only workaround I have found
is to toggle Auto Mute off and on again after plugging the headphones
in. This somehow resets the setup and gets it to do the right thing.

Btw, what is the actually definition of "Auto Mute"? I think it means
that only one of internal speakers or headphones should be active at one
time. Is this correct?