Skype bi-directional video call crashes X server (xserver, mesa, drm, kernel from git, r600g+glamor)

[Kertesz Laszlo]

On Tue, 2014-10-28 at 09:41 -0400, Alex Deucher wrote: 
> On Tue, Oct 28, 2014 at 8:13 AM, Laszlo Kertesz
> <laszlo.kertesz at gmail.com> wrote:
> > Hello,
> > i have an issue with Skype lately (i compile mesa, kernel, drm, xserver from
> > git periodically and i use a A8-6500 with its IGP with r600g and glamor).
> > It crashes the x server if i use bi directional video call. It seems to work
> > in one-way video.
> > The x server restarts, but skype  continues to work for about half a minute
> > more, including sending video.
> > One problem is that i dont see any errors in any logs, not dmesg or xorg log
> > so i cant say which component is the culprit.
> >
> > Now it seems that a similar issue existed in the past and it was related to
> > some drivers that couldnt handle multiple xv instances (one for the received
> > video, the other for the local video thumbnail). And there was a workaround
> > of disabling the local video thumbnail which cant be done on the current
> > Skype (4.3). The glamor xv reports 16 available ports though.
> >
> > Is there any other way of diagnosing this error? Maybe i have some issue
> > with the 32 bit driver installation?
> > Although i had no problems whatsoever (gaming on Steam, vdpau etc works well
> > for example) other than this.
> >
> 
> Attach gdb to the xserver and get a backtrace when it crashes.  Make
> sure you install the debug symbols for the xserver, etc.
> http://www.x.org/wiki/Development/Documentation/ServerDebugging/
> 
> Alex

I idd a bdb trace a while back and it does seem incomplete probably
because something wasnt compiled with debug on.

Program received signal SIGABRT, Aborted.
0x00007f530e3d5077 in __GI_raise (sig=sig at entry=6)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56 ../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
Continuing.
[Thread 0x7f53083d7700 (LWP 32676) exited]

Program terminated with signal SIGABRT, Aborted.
The program no longer exists.

Anyway, the cause is clearly glamor on r600g related as i have disabled
glamor and on exa i did not have any such issues.
Even with the newest xserver git build it does crash nonetheless.

last commit is 
glamor: Make sure glamor_egl_close_screen wraps glamor_close_screen