[Intel-gfx] black screen if sna & TearFree

[Grant]

>>> 'xset dpms force off; sleep 1; xset dpms force on' does indeed trigger
>>> the error.  I've attached my Xorg.0.log.old which includes the
>>> segfault backtrace.  I'm like a newborn baby when it comes to
>>> compiling and Gentoo doesn't have a debug USE flag for
>>> xf86-video-intel or xorg-server so I can't help there.  Is there a
>>> different package I should check for a debug USE flag?
>>
>> In the Xorg.log, the first error appears to be a failed modeset after
>> resume:
>>
>> [  5131.319] (II) AIGLX: Resuming AIGLX clients after VT switch
>> [  5131.319] (II) intel(0): switch to mode 1366x768 on crtc 3 (pipe 0)
>> [  5131.319] (EE) intel(0): failed to set mode: Invalid argument
>> [  5131.319] (WW) intel(0): failed to restore desired modes on VT switch
>>
>> That is going to leave the screens blank. And the subsequent segfault
>> suggests that I don't have sufficient safeguards to handle that failure.
>> Can you please run 'addr2line -e
>> /usr/lib64/xorg/modules/drivers/intel_drv.so 0xb9ed7 0x68517 0x5aa2e' ?
>
> I reproduced the segfault on my other (identical) laptop and got:
>
> [ 10865.673] 3: /usr/lib64/xorg/modules/drivers/intel_drv.so
> (0x7f5cf32f5000+0x39ba5) [0x7f5cf332eba5]
> [ 10865.673] 4: /usr/lib64/xorg/modules/drivers/intel_drv.so
> (0x7f5cf32f5000+0x47015) [0x7f5cf333c015]
> [ 10865.673] 5: /usr/lib64/xorg/modules/drivers/intel_drv.so
> (0x7f5cf32f5000+0x4bc29) [0x7f5cf3340c29]
> [ 10865.673] 6: /usr/lib64/xorg/modules/drivers/intel_drv.so
> (0x7f5cf32f5000+0x57708) [0x7f5cf334c708]
>
> so I changed the command:
>
> # addr2line -e /usr/lib64/xorg/modules/drivers/intel_drv.so 0x39ba5
> 0x47015 0x4bc29 0x57708
> ??:0
> ??:0
> ??:0
> ??:0
> #
>
>> To solve what happened to prevent the modeswitch we need to have the
>> dmesg, preferrably with drm.debug=6 (echo 6 >
>> /sys/modules/drm/parameters/debug).
>
> I've attached kern.log since the segfault.  It looks like there's some
> good stuff in there.
>
>> Compiling a debug driver is pretty straightforward.
>> $ git clone git://anongit.freedesktop.org/xorg/driver/xf86-video-intel
>> $ cd xf86-video-intel
>> $ ./autogen.sh --prefix=/usr --enable-debug=full
>> $ make && sudo make install
>>
>> This will overwrite the system driver and so not need any modification
>> to config files. (It is possible to install into local and change
>> /etc/X11/xorg.conf to load the driver from there.) So just reinstall
>> your distro package to revert.
>> -Chris
>
> If it's still necessary for me to do so, please tell me how to install
> into a folder (/usr/local ?) that I can delete later to completely
> wipe out the install.
>
> Thanks,
> Grant

Hi, have you had a chance to look into this?

- Grant