headphone jack on Thinkpad T61?

[Steven Bellovin <smb%cs.columbia.edu@localhost>]

On a Thinkpad T61 running 5.1_STABLE, the volume from the headphone jack
is extremely low.  We've bumped up every gain value in sight (i.e.,
anything with two number and a comma in mixerctl output...).  Any idea
what to do about this?  (It took enough work to figure just how to
turn the headphones on...)

                --Steve Bellovin, https://www.cs.columbia.edu/~smb