[ltp] Internal speakers are on although stereo jack plugged

[Henrique de Moraes Holschuh]

On Tue, 03 Jul 2007, Achim Bosch wrote:
> when i plug the stereo jack in my dock, the internal speakers of my T43 don't  get mute.

No, they don't.

> The internal speakers only mute when i plug directly into my laptop.
> Does anybody have a solution? Is this a problem with ALSA or with the hardware?

This is done by design.

Here's the audio routing on a T43 (use a monospaced font to see):

AC97 Mixer --->---+----->----- ThinkPad Mixer ->--+-- (speakers)
                  |                  |            +-- (headphone out)
                  |                  ^
                  |                  |
                  |           (EC beep generator)
                  |
                  +-->-- (dock output)

So, the dock sound output has none of the firmware alarm sounds (careful with
this!), and is under control of the AC97 mixer, only.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh