Hard lockup with dual radeon x86_64

[Wayne W. <wh...@po...>]

Hello,

I have been a long time happy user of ruby using dual Radeon 7000 cards
(one AGP and one PCI).  Recently I upgraded my system from Athlon XP with
Fedora Core 3 to Athlon 64 with Fedora Core 4.  Now any attempt to access
the PCI card locks up my computer [background mpg321 starts stuttering,
Alt-SysRq-B will not reboot].  This includes 'X -configure' (although the
Fedora Core 4 installer didn't crash) and occurs with patched or stock
(FC4) xorg 6.8.2 and customized or stock kernel 2.6.11.

Any thoughts on how to start debugging this?  Obviously a hard lockup is
difficult to deal with.  I seem to recall that one other user on this list
also has dual radeons on x86_64, is there something I'm missing?  Any help
would be very appreciated.  I've tried already the radeon VGAAccess patch,
that does not help with the lockup.

Thanks, Wayne

P.S.  Updating from Fedora Core 3 to Fedora Core 4 may have had the effect
of updating xorg from 6.8.1 to 6.8.2, since I'm not sure I kept up with
the FC3 xorg updates.  And obviously I had to recompile my kernel.  So I
guess these are other possible candidates.