Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic

From: Pavel Machek
Date: Thu May 28 2009 - 16:31:00 EST


Hi!

> > @hpa - I still like your suggestion that it is only one (or a few)
> > uses of atomic ops that is incorrect and in general atomic ops
> > should compile away on uni-processor.
> >
>
> Actually, the more I think about it the more I suspect there is a race
> condition either in the chip set or in any VIA-specific drivers (if
> there are any.) Putting LOCKs in random places will slow the CPU down
> significantly, so it might resolve the race condition without actually
> solving the problem.

Which you can verify; replace lock with something slow (pushad,
popad)? And see what happens.

(And if it never ever triggers on hp2133, you have strong clue that it
may not be cpu-related, but bios-related or chipset related or something).

Some time ago I was trying to debug misterious hangs on some
via/fic machines.

We never figured out what was wrong, but we discovered many other bios
bugs, and those were not being fixed; so debugging was
hard/impossible. Unfortunately I no longer have access to that hw.

hp2133 did _not_ have that problem.

Try forcing maximum throttling, then move mouse for like five
seconds. If kbc dies, you have same buggy bios, and probably are
debugging same problem....
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/