Comment # 2 on bug 916048 from Troels Just

(In reply to Takashi Iwai from comment #1)
> Could you check whether it's a problem of PulseAudio or the driver itself?
> For example,
> - Go to runlevel 3 and login
> - Make sure that no pulseaudio process is running
> - Unmute and adjust the level of both "Headphone" and "Speaker" via
> "alsamixer -c0"
> - Play something via "aplay -Dplughw something.wav"
> - Plug or unplug the headphone, test playing.  Check whether pulseaudio is
> really not running meanwhile.
> 
> If the test above passes, the problem is in PulseAudio.  If the above fails,
> it's a driver issue.

If I can just jump in. I have two friends running openSUSE 13.2, and both of
them have this problem, and I just reproduced it on my ThinkPad X230.

I just performed the steps you suggested as a test. When running in runlevel 3,
I made sure that both speakers and headphones were unmuted, and set to their
maximum volume. I then used "mplayer -ao alsa" play something (Checking both
before and after that PulseAudio was not running). There were no problems
playing on the speakers, I then plugged in the headphones and the sound went to
the headphones, I then unplugged the headphones sound went back on the
speakers, no issue here.

I also tried using GNU screen to start the music playing, and then keeping an
eye on the mixer volumes via alsamixer at the same time. And what I noticed is
that when running without PulseAudio in runlevel 3, the mixer levels do not
change at all head plugging/unplugging the headphones. So nothing seems to be
wrong at the driver-level.

What I noticed in runlevel 5 (I run KDE, GNOME users might want to report if
they have the same issue), and why I think this is a PulseAudio issue, is that
when I plug in my headphones, the Speaker-volume gets muted, and the headphones
unmuted, but when I unplug the headphones the reverse does NOT happen. So it
seems to me that this issue can be summed up as PulseAudio not unmuting the
speaker and re-muting the headphones.

Finally, I think I also noticed this issue in a different way. Last night, I
connected my X230 to my TV via a Mini-DiplayPort-to-HDMI cable, and I noticed
the sound automatically going to the TV, good stuff. But when I unplugged the
cable, the sound went quiet on the speakers, and when I plugged in the cable
again, the sound played on the TV.

This seems to be a larger issue of PulseAudio not reversing mixer changes when
dealing with plugging/unplugging.