when run mesa demo "fire" for a while, it resulted in seg fault then crashed Xorg. 
If start Xorg again, there is response when run any 3D app.
Our platform is GM965.
source version:
Xf86_video_intel:       master branch 75ef3e669dac1259d282dcc8f54b197fc19f22b3
Drm:            309b2c4c05d02a7e7311a9491b74044f6c7f06a4
Xserver:                23b8ca8a373d919225de9739af7b064f650eceec
Mesa:     965-ttm branch      9f2501cff51a5b1cbc2e984e54f3166d42e1af6c

Below is the seg fault info:

Program received signal SIGSEGV, Segmentation fault.
0x00002b0a82e50043 in memcpy () from /lib/libc.so.6
(gdb) bt
#0  0x00002b0a82e50043 in memcpy () from /lib/libc.so.6
#1  0x00002b0a849764ce in dri_bo_subdata (bo=0x8fe450, offset=0, size=560,
    data=0x7fff28476510) at ../common/dri_bufmgr.c:119
#2  0x00002b0a8499fb4d in brw_upload_cache (cache=0x629da8,
    key=<value optimized out>, key_size=8, data=0x7fff28476510, data_size=560,
    aux=0x7fff2847b080, aux_return=0x62abe8) at brw_state_cache.c:190
#3  0x00002b0a849a11e9 in brw_upload_vs_prog (brw=0x615fb0) at brw_vs.c:78
#4  0x00002b0a849a04c3 in brw_validate_state (brw=0x615fb0)
    at brw_state_upload.c:256
#5  0x00002b0a84994820 in brw_set_prim (brw=0x615fb0, prim=0) at brw_draw.c:108
#6  0x00002b0a84994b05 in brw_draw_prims (ctx=0x615fb0, arrays=0x651ca0,
    prim=0x650484, nr_prims=1, ib=0x0, min_index=0, max_index=3)
    at brw_draw.c:300
#7  0x00002b0a84a3302c in vbo_exec_vtx_flush (exec=0x650240)
    at vbo/vbo_exec_draw.c:215
#8  0x00002b0a84a2e7c9 in vbo_exec_FlushVertices (ctx=<value optimized out>,
    flags=675767568) at vbo/vbo_exec_api.c:685
#9  0x00002b0a84ad70cc in _mesa_set_enable (ctx=0x0, cap=3008, state=0 '\0')
    at main/enable.c:238
#10 0x00002b0a84ad8e4b in _mesa_Enable (cap=3008) at main/enable.c:976
#11 0x00002b0a82a07b06 in glEnable (cap=3008)
    at ../../../src/mesa/glapi/glapitemp.h:1160
#12 0x0000000000402704 in drawfire () at fire.c:456
#13 0x00002b0a82656ea4 in processWindowWorkList (window=0x60b390)
    at glut_event.c:1306
#14 0x00002b0a826579e2 in glutMainLoop () at glut_event.c:1353
#15 0x00000000004038cd in main (ac=1, av=<value optimized out>) at fire.c:774