I tend to agree with Stephen's analysis. We actually need to keep the
pullup enabled unless we are actually turning power off to the codec,
which we don't seem to be doing.
I guess I'm a little surprised that we don't even seem to turn any of
this codec's regulators off in S3. That seems like it would be drawing
power that we don't want. Maybe the "low power" mode of the codec is
low enough and we need to avoid powering it off to avoid pops / hisses
in S3 or something? If that's true, this might be one of those places
where the "LPM" of the regulators might actually be useful...