FedoraCore4 X woes

[D. Hugh Redelmeier]

Talking in the bar after this weeks meeting, I realised that a certain
Fedora Core 4 bug in X was probably hitting a member and that he
didn't know of the bug.  Maybe others of you are hitting this too.

This bug seems to make X misbehave on a variety of hardware.  The root
cause is that GCC4 (new, and first introduced in Fedora with FC4)
miscompiles some code with the C "volatile" type qualifier.

The key information is in Redhat's Bugzilla:
	https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=161242
But that may be too long and boring for you.

The simplest fix is partially described in message #3 in the thread
(assuming that you are on i386 and not x86_64).  Grab the replacement
libvgahw.a file and replace the existing version with it:
	/usr/X11R6/lib/modules/libvgahw.a
(Do keep a backup of what you replace.)
Reboot, including a power cycle -- that reduces the chance of any bad
state remaining in the hardware.

So far, later proposed fixes seem to be more trouble or less likely
to succeed.

Note: I've not tried this fix.  I'm boycotting FC4 until they fix the
bug in GCC4.  This might take a while since the GCC maintainers don't
agree that it is a bug.  A close reading of the C standard shows that
it is a bug (Henry has made such an analysis).
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