Re: [PATCH 4/8] 8xx: Fixup DAR from buggy dcbX instructions.

Scott Wood [off-list ref] wrote on 14/10/2009 22:22:25:

Joakim Tjernlund wrote:

quoted

Scott Wood [off-list ref] wrote on 14/10/2009 21:23:02:

quoted

Joakim Tjernlund wrote:

quoted

BTW, you could add a test and printk in do_page_fault on address 0x000000f0.
if that ever hits there is a problem with dcbX fixup.

It doesn't get any 0xf0 faults.

FWIW, I'm not seeing the segfault any more, but I still get the lockup.

Have you reverted
 8xx: start using dcbX instructions in various copy routines ?

After that you could stick a
 b DataAccess

 directly in the DTLB error handler to skip and dcbX fixups.

With that, I don't see the hard lockup, but things get stuck during

You needed both to loose the hard lockup? I would think
it should be enough to revert the "various copy routines" stuff?
I figure that these routines aren't working in 8xx for other reasons
since they haven't been used on 8xx since at least early 2.4.

bootup with everything idle.  I see this even if I revert everything but
the "invalidate non present TLBs" patch, and I was seeing similar things
sometimes with the other tlbil_va hacks.

OK, something else is up.

I think there's something else going on in the 2.6 8xx code that needs
to be fixed before we can tell what the impact of these patches is.
I'll look into it.

Great because I am really out of ideas. Perhaps back down to 2.6.30 and test
from there?