solved, kinda (Re: Can't start Xorg after upgrade -- radeon R200)

[Niclas Zeising]

On 05/14/13 22:40, Mikhail T. wrote:
> 14.05.2013 15:41, Mikhail T. написав(ла):
>>
>> I upgraded this older machine from 8.3 to 9.1 over the weekend.
>> Everything continued to function smoothly after the OS/kernel update,
>> but then I rebuilt all of the ports and rebooted...
>>
>> Xorg would no longer start:
>>
>>     AddScreen/ScreenInit failed for driver 0
>>
> Rebuilding x11/xorg-server with cc (rather than gcc47 as all the other
> ports were built) solves the problem.
> 
> I'm puzzled, why it matters, but I can reliably break and restore Xorg
> start-up by switching between the cc- and gcc47-built versions of the
> binaries. No other changes. All of the drivers (mouse, keyboard, ati)
> remain compiled by gcc47.

xorg, and especially the old xorg-server used by default in FreeBSD
ports is riddled with weird code and undefined behavior.  A change of
compiler will trigger different optimizations which might break
assumptions about things.  I've seen it before, especially when
switching between gcc and clang.  You might want to test using clang
instead, or rebuild all xorg ports with WITH_NEW_XORG= to get a more
recent xorg version.  Otherwise, I suggest you keep running with your
gcc based xorg-server, unless you have the time and ability to debug the
issue further.
Regards!
-- 
Niclas Zeising