Radeon HD 6530D crashing Xorg with a CentOS 6.6 kernel

Michel Dänzer michel at daenzer.net
Mon Jan 5 19:13:17 PST 2015

On 06.01.2015 12:03, Darby Vicker wrote:
> On Sat, Jan 3, 2015 at 11:10 PM, Darby Vicker <darby.vicker at gmail.com> wrote:
>> On Wed, Dec 24, 2014 at 7:58 PM, Michel Dänzer <michel at daenzer.net> wrote:
>>> On 24.12.2014 22:26, Darby Vicker wrote:
>>>> On Wed, Dec 24, 2014 at 12:50 AM, Michel Dänzer <michel at daenzer.net> wrote:
>>>>> On 24.12.2014 14:18, Darby Vicker wrote:
>>>>>> On Tue, Dec 23, 2014 at 9:02 PM, Michel Dänzer <michel at daenzer.net> wrote:
>>>>>>> On 23.12.2014 14:11, Darby Vicker wrote:
>>>>>>>> Hello,
>>>>>>>> Sorry for the cross post but I figure this is a better place to get
>>>>>>>> help.  With the Xorg ABI update in CentOS/RHEL 6.6 [1] I can't get X
>>>>>>>> to come up properly.  More info in this thread on the CentOS list:
>>>>>>>> http://lists.centos.org/pipermail/centos/2014-December/148341.html
>>>>>>>> To summarize:
>>>>>>>> * Stock ATI drivers shipped with CentOS crash X with a 6.6 kernel
>>>>>>>> * fglrx drivers also crash X with a 6.6 kernel[2]
>>>>>>>> * a centos 6.6 livecd still exibits the problem (trying to rule out an
>>>>>>>> issue with my specific installation)
>>>>>>>> I have Xorg.0.log files for boots from the 4 combinations of boots
>>>>>>>> from a CentOS 6.5 and 6.6 kernel and the stock and fglrx drivers.
>>>>>>>> Nothing obvious stands out to me but I could definitely be missing
>>>>>>>> something.  What's the best way to send the logs - just inline?
>>>>>>> Please attach the *.stock log files.
>>>>>> Sure - attached.
>>>>> I can't see any graphics driver related problem in
>>>>> Xorg.0.log.centos6.6.stock.gz; the X server seems to start up and shut
>>>>> down cleanly.
>>>>> Why do you think the graphics drivers crash? Maybe the problem is on the
>>>>> client side, e.g. related to gdm or the login manager you're using.
>>>> I should be more specific about the problem.  The problem occurs at
>>>> the point where the boot splash screen transitions to when (I assume)
>>>> X starts and the login screen comes up.  When I boot the CentOS 6.6
>>>> kernel, the screen just goes black and shortly after that the monitor
>>>> goes to sleep with a "No signal" message.  The virtual terminals (e.g.
>>>> cntl-alt-F2) don't work at that point either.  I was assuming that
>>>> since the Xorg ABI has changed between the CentOS 6.5 and 6.6 release,
>>>> it was very likely that the problem was related to Xorg.
>>> If there was a Xorg ABI issue, you could see in the Xorg log file that
>>> the driver fails to load.
>>>> Do you have any suggestions for isolating the problem?  I'm not sure what else to
>>>> try.  I did also try a boot to single user mode with the 6.6 kernel
>>>> and then did a "startx".  My thought was to try to start X with
>>>> minimal other services started to see if something else was
>>>> interfering with X.  But the same thing happens - the screen goes
>>>> blank and the monitor goes to sleep.  Any other suggestions are
>>>> welcomed.
>>> If you boot the 6.5 kernel, does it still work with the same userspace
>>> that shows the problem with the 6.6 kernel? If so, it sounds like
>>> there's just some regression in the 6.6 kernel. Maybe there's something
>>> in dmesg, or maybe you can try isolating the change between the 6.5 and
>>> 6.6 kernels which caused the regression.


> Do you know if there is a way to bypass gdm to see if that is the
> problem?  For example, is there an alternative to GDM or some way to
> try to start the X-session directly?

You can log into console and start X via startx or xinit.

However, it sounds like a kernel change at least triggers the problem.
You should probably get in touch with the people maintaining the CentOS
kernel, they should be able to help you isolate which change that is.

Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer

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