intel 855: crash after playing xv and vt switch - reg dumps

[Willi Mann]

> Thanks for letting us know. It does fix a blue-overlay followed by
> lockup (/ hang?) on the 945GM with overlay video (forced as opposed to
> textured video by an Ubuntu patch).

I had screen corruptions earlier, but they are fixed in master.

> I posted against the 855 XV bug thinking that it was the same issue
> being seen, but this might not have been the case.

> Do your symptoms match those I described above? (When returning from VT,
> the XV overlay window is blue for a couple of seconds, followed by a
> lockup?)

No, the lockup always occurs when I switch to plain VT, and this causes
the lockup and then the segfault in the lockup handling code, and the
server is killed - I have NoTrapSignals enabled, otherwise the machine
would freeze (Which is probably another bug) - look at the backtrace I
provided last time.

> There are some other bugs affecting VT switching on the 855 driver, do
> you have any patches for those in your sources?

I had applied your patches you posted last time, and they helped to fix
the complete machine hang, but they don't help with the XV lockup bug.
(The problem with the machine hang bug is that it does not occur always
so it is just likely, but not absolutely sure it helped, so I refrained
from reporting a success, especially as I'd like to first identify the
patch that helped - I've applied all your patches). But the register
dumps are with plain master. I have uploaded a second series of register
dumps to http://wserver.wm1.at/~willi/xorg-dump2/ maybe anyone can make
use of them for fixing the bug.

> There is one attached to the end of this bug:
> https://bugs.freedesktop.org/show_bug.cgi?id=12297

This is the patch that I suppose helped.

Willi