[ 11720.890] (EE) 
[ 11720.890] (EE) Backtrace:
[ 11720.891] (EE) 0: /usr/bin/X (xorg_backtrace+0x4f) [0xb7692c0f]
[ 11720.891] (EE) 1: /usr/bin/X (0xb74eb000+0x1ab9e4) [0xb76969e4]
[ 11720.891] (EE) 2: linux-gate.so.1 (__kernel_rt_sigreturn+0x0) [0xb74c9ac4]
[ 11720.891] (EE) 3: /usr/lib/i386-linux-gnu/dri/radeonsi_dri.so (0xb657f000+0x45835) [0xb65c4835]
[ 11720.891] (EE) 4: /usr/lib/i386-linux-gnu/dri/radeonsi_dri.so (0xb657f000+0x44540) [0xb65c3540]
[ 11720.891] (EE) 5: /usr/lib/i386-linux-gnu/dri/radeonsi_dri.so (0xb657f000+0x1a6a88) [0xb6725a88]
[ 11720.891] (EE) 6: /usr/lib/i386-linux-gnu/dri/radeonsi_dri.so (0xb657f000+0x181a70) [0xb6700a70]
[ 11720.891] (EE) 7: /usr/lib/i386-linux-gnu/dri/radeonsi_dri.so (0xb657f000+0x11de22) [0xb669ce22]
[ 11720.891] (EE) 8: /usr/lib/xorg/modules/libglamoregl.so (0xb6c64000+0x13ca) [0xb6c653ca]
[ 11720.891] (EE) 9: /usr/lib/xorg/modules/libglamoregl.so (glamor_egl_create_argb8888_based_texture+0xa6) [0xb6c65736]
[ 11720.891] (EE) 10: /usr/lib/i386-linux-gnu/libglamor.so.0 (0xb6c1a000+0x27e5a) [0xb6c41e5a]
[ 11720.891] (EE) 11: /usr/lib/i386-linux-gnu/libglamor.so.0 (0xb6c1a000+0x2847c) [0xb6c4247c]
[ 11720.891] (EE) 12: /usr/lib/i386-linux-gnu/libglamor.so.0 (glamor_create_pixmap+0x2cb) [0xb6c1d60b]
[ 11720.891] (EE) 13: /usr/lib/xorg/modules/drivers/radeon_drv.so (0xb6c6a000+0x49810) [0xb6cb3810]
[ 11720.891] (EE) 14: /usr/bin/X (0xb74eb000+0x3812c) [0xb752312c]
[ 11720.891] (EE) 15: /usr/bin/X (0xb74eb000+0x3cb0d) [0xb7527b0d]
[ 11720.891] (EE) 16: /usr/bin/X (0xb74eb000+0x40c25) [0xb752bc25]
[ 11720.891] (EE) 17: /usr/bin/X (0xb74eb000+0x2a93e) [0xb751593e]
[ 11720.892] (EE) 18: /lib/i386-linux-gnu/libc.so.6 (__libc_start_main+0xf3) [0xb70af723]
[ 11720.892] (EE) 19: /usr/bin/X (0xb74eb000+0x2a974) [0xb7515974]
[ 11720.892] (EE) 
[ 11720.892] (EE) Segmentation fault at address 0x8
[ 11720.892] (EE) 
Fatal server error:
[ 11720.892] (EE) Caught signal 11 (Segmentation fault). Server aborting
[ 11720.892] (EE) 
[ 11720.892] (EE) 
Please consult the The X.Org Foundation support 
	 at http://wiki.x.org
 for help. 
[ 11720.892] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[ 11720.892] (EE) 
[ 11720.892] (II) AIGLX: Suspending AIGLX clients for VT switch
[ 11720.914] (EE) Server terminated with error (1). Closing log file.