Radeon HD 6530D crashing Xorg with a CentOS 6.6 kernel

[Darby Vicker]

On Mon, Jan 5, 2015 at 9:13 PM, Michel Dänzer <michel at daenzer.net> wrote:
> 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

Good point, I've actually already done that.  I booted into single
user mode and did a startx - something still goes wrong (the screen
goes blank and the monitor then goes to sleep).  I'll try to see if
the CentOS/RHEL kernel maintainers can help.  Thanks.