[ 29137.734] (EE) 
[ 29137.734] (EE) Backtrace:
[ 29137.734] (EE) 0: /usr/bin/X (xorg_backtrace+0x4e) [0x58cf3e]
[ 29137.734] (EE) 1: /usr/lib64/xorg/modules/drivers/intel_drv.so (0x7f4a91863000+0x16e7f5) [0x7f4a919d17f5]
[ 29137.734] (EE) 2: /usr/bin/X (DRI2SwapBuffers+0x1c8) [0x560918]
[ 29137.734] (EE) 3: /usr/bin/X (0x400000+0x1621ac) [0x5621ac]
[ 29137.734] (EE) 4: /usr/bin/X (0x400000+0x35f4b) [0x435f4b]
[ 29137.734] (EE) 5: /usr/bin/X (0x400000+0x3a088) [0x43a088]
[ 29137.734] (EE) 6: /lib64/libc.so.6 (__libc_start_main+0xf0) [0x7f4a95df92c0]
[ 29137.734] (EE) 7: /usr/bin/X (_start+0x2a) [0x423faa]
[ 29137.734] (EE) 
[ 29137.734] (EE) 
Fatal server error:
[ 29137.734] (EE) sna_dri2_schedule_swap:3321 assertion 'get_private(back)->bo != get_private(front)->bo' failed
[ 29137.734] (EE) 
[ 29137.734] (EE) 
Please consult the The X.Org Foundation support 
         at http://wiki.x.org
 for help. 
[ 29137.734] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[ 29137.734] (EE) 
[ 29137.734] (II) AIGLX: Suspending AIGLX clients for VT switch
[ 29137.838] (EE) Server terminated with error (1). Closing log file.