Comment 14 for bug 394500

I think I've found a temporary workaround (not a solution).

I've opened /etc/pulse/default.pa and commented 4 lines.

Before:

### Automatically load driver modules depending on the hardware available
.ifexists module-udev-detect.so
load-module module-udev-detect
.else
### Alternatively use the static hardware detection module (for systems that
### lack udev support)
load-module module-detect
.endif

After:

### Automatically load driver modules depending on the hardware available
#.ifexists module-udev-detect.so
#load-module module-udev-detect
#.else
### Alternatively use the static hardware detection module (for systems that
### lack udev support)
load-module module-detect
#.endif

Then I killed/restated pulseaudio and now I have audio input/output from the internal audio device.

Still, the Hardware tab under Sound Preferences is empty, as if there was no audio device available.

Sound Preferences > Hardware > Choose a device to configure: > (empty field)