[alsa-devel] No sound from internal speaker on 2013 Macbook Air 6, 1

[Ben Whitten]

> > > OK, then the normal jack detection doesn't work with this machine, as
> > > it seems.  You can try the above to all pins for checking if any of
> > > other pins reacts to the headphone jack.
> >
> > No luck I'm afraid - none of the other pins seem to react to the
> > headphones. Is there anything else you can think of that I can try
> > tomorrow?
>
> Well, it might be notified via GPIO.  Try to read GPIO pins except for
> GPIO0.  That is, set the all unmasked, the direction to READ.

We have found that jack sense comes in on the headphone pin in a windows
bootcamp install. However this bit isn't set in linux using either the
default chip, bootloader, or windows pin configs. No other GPIO's are
enabled in windows.

Ben