Comment # 15 on bug 1039700 from Oliver Kurz

Now I let the system run over night and it's stuck in the locking screen, the
mouse cursor still moves. So I collected a back trace on kwin_x11 instead. Full
output is available in http://susepaste.org/30285788 .

What looks suspiciuous to me now is the following section

```
Thread 1 (Thread 0x7fd02c168940 (LWP 2883)):
#0  0x00007fd02b8c349d in poll () at ../sysdeps/unix/syscall-template.S:84
#1  0x00007fd02aa473e2 in poll (__timeout=-1, __nfds=1, __fds=0x7ffc275fefe0)
at /usr/include/bits/poll2.h:46
#2  _xcb_conn_wait (c=c@entry=0x1be81b0, cond=cond@entry=0x7ffc275ff100,
vector=vector@entry=0x0, count=count@entry=0x0) at xcb_conn.c:459
#3  0x00007fd02aa48d1f in wait_for_reply (c=c@entry=0x1be81b0,
request=request@entry=76426, e=e@entry=0x7ffc275ff1c8) at xcb_in.c:516
#4  0x00007fd02aa48e92 in xcb_wait_for_reply64 (c=c@entry=0x1be81b0,
request=76426, e=e@entry=0x7ffc275ff1c8) at xcb_in.c:560
#5  0x00007fd0224ff110 in _XReply (dpy=dpy@entry=0x1be6f50,
rep=rep@entry=0x7ffc275ff240, extra=extra@entry=0, discard=discard@entry=0) at
xcb_io.c:596
#6  0x00007fd02146ede3 in DRI2GetBuffersWithFormat (dpy=0x1be6f50,
drawable=50331657, width=width@entry=0x1e95f48, height=height@entry=0x1e95f4c,
attachments=0x7ffc275ff320, count=1, outCount=outCount@entry=0x7ffc275ff31c) at
dri2.c:491
#7  0x00007fd02146f0eb in dri2GetBuffersWithFormat (driDrawable=<optimized
out>, width=0x1e95f48, height=0x1e95f4c, attachments=<optimized out>,
count=<optimized out>, out_count=0x7ffc275ff31c, loaderPrivate=0x1e47ce0) at
dri2_glx.c:894
#8  0x00007fd00c88342a in intel_query_dri2_buffers
(buffer_count=0x7ffc275ff31c, buffers=<synthetic pointer>, drawable=0x1e95f20,
brw=0x7fd00bc43040) at brw_context.c:1575
#9  intel_update_dri2_buffers (drawable=0x1e95f20, brw=0x7fd00bc43040) at
brw_context.c:1413
#10 intel_update_renderbuffers (context=context@entry=0x1df4ed0,
drawable=drawable@entry=0x1e95f20) at brw_context.c:1469
#11 0x00007fd00c88386f in intel_prepare_render (brw=brw@entry=0x7fd00bc43040)
at brw_context.c:1488
#12 0x00007fd00c884719 in brw_try_draw_prims (indirect=0x0, stream=0,
xfb_obj=0x0, max_index=4294967295, min_index=4294967295,
index_bounds_valid=false, ib=0x7ffc275ff470, nr_prims=1, prims=0x7ffc275ff490,
arrays=0x20ea638, ctx=0x7fd00bc43040) at brw_draw.c:478
#13 brw_draw_prims (ctx=0x7fd00bc43040, prims=0x7ffc275ff490, nr_prims=1,
ib=0x7ffc275ff470, index_bounds_valid=<optimized out>, min_index=4294967295,
max_index=4294967295, gl_xfb_obj=0x0, stream=0, indirect=0x0) at brw_draw.c:688
```

so is it about the Intel graphics driver after all? Takashi, can you please
take a second look here?