4.0/i386 auich_calibrate() and GENERIC.NOACPI failure (microtime?)

[Chuck Cranor <chuck%ece.cmu.edu@localhost>]

hi-

    I updated my i386/desktop to 4.0 yesterday, and discovered that the 
audio auich0 does not configure properly with the GENERIC.NOACPI kernel.
It might be timecounter related?

GENERIC kernel (correct audio):
  auich0: measured ac97 link rate at 55069 Hz, will use 55000 Hz


GENERIC.NOACPI (audio plays at wrong rate):
  auich0: measured ac97 link rate at 43170 Hz, will use 48000 Hz


55000 Hz is the correct value, 48000 Hz sounds wrong (music too fast).

the auich driver uses the hardware and microtime() to compute the 
ac97 link rate.   The GENERIC kernel uses kern.timecounter.hardware=ACPI-Fast,
where as the GENERIC.NOACPI uses kern.timecounter.hardware=i8254.


    Anyone have any suggestions on how to debug this?   Here are
some links to dmesg output:

  GENERIC:        http://yogi.pdl.cmu.edu/~chuck/40/dmesg-gen.txt
  GENERIC.NOACPI: http://yogi.pdl.cmu.edu/~chuck/40/dmesg-noacpi.txt


chuck