Started back in mid-May - long time and a lot of hours later...
As suggested very early in this examination by others -
It is a timing issue. My inserting "lock" for config_mviac7
was just poking at the edges of the sore spot. ;)
The "break through" came yesterday while running (or trying to run)
FreeBSD-8.0-beta2 on the various machines at hand. . .
Depending on the cpu model variation and the integrated chipset
used with that cpu - -
*) FB-8.0 will run
*) FB-8.0 will only run in "safe mode"
*) FB-8.0 panics
And that pattern is similar to the 2.6.30 cpu model / chipset pattern.
Scratches head, asking: "now how can that be" with two very different OS designs.
Diddling with the things I have found that either "fix" or "work around"
the various timing / cache coherency issues - - -
Aw, so - found how to affect the timing issues sufficiently so that Linux
would panic dump rather than deadlock on the troublesum combination - -
*Functionally the same* panic backtrace that FreeBSD is showing.
NOW I have a lead into making a "minimum invasive" change so that the
kernel is happy - even on the flaky VIA combinations. Patch RSN, just any month.
The FreeBSD project can fix their problems themselves. ;)
@H.W. Download the FreeBSD-8.0-beta2 and try running it on your Cloudbook and HP-2133,
you can see what is happening. Then you might have a word or two with the silicon growers.
Mike