Re: 4.0/i386 auich_calibrate() and GENERIC.NOACPI failure

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

>It could really just be a side effect of the extremely slow i8254.
>Can you try adding the ichlpcib for the noacpi case?
>Joerg

hi-

    I added:

ichlpcib* at pci? dev ? function ?     # Intel ICH PCI-ISA w/ watchdog and
isa0   at ichlpcib?

to GENERIC.NOACPI, but it didn't fix the auich0 problem:

[ http://yogi.pdl.cmu.edu/~chuck/40/dmesg-ichlpcib.txt ]
auich0: measured ac97 link rate at 43212 Hz, will use 48000 Hz

rather than the expected 55000 Hz.


    But I did some poking around and discovered that this broke
in Sept of 2006.   A binary search showed that kernels compiled
from a Sept 2006 1st, 8th, and 10th source tree work fine, but 
kernels compiled from Sept 2006 11th, 12th, and 15th did not.
The key even was the commit of rev 1.12 of kern_rc.c on the 10th.


    Working with a 4.0 release tree, things also work OK if you 
just revert kern_tc.c back to 1.11 (keeping everything else at 4.0).


    This makes me think it is spl() related.   Is it possible
that interrupts are invalidating the measurement that auich_calibrate() 
is trying to do?


chuck