(gdb) c
Continuing.

Program received signal SIGSEGV, Segmentation fault.
0x00007f380477dfbd in radeon_cs_flush_indirect (pScrn=0x24b81b0) at radeon_kms.c:78
78    if (!info->cs->cdw)
(gdb) p info->cs
$1 = (struct radeon_cs *) 0x0
(gdb) bt
#0  0x00007f380477dfbd in radeon_cs_flush_indirect (pScrn=0x24b81b0) at radeon_kms.c:78
#1  0x00007f380473a7ef in RadeonCompositeTileCP (pScrn=0x24b81b0, info=0x24bb450, pDst=0x4aad820, srcX=0, srcY=0, maskX=480, maskY=27, dstX=480, dstY=20, w=5, h=5)
    at radeon_exa_render.c:2182
#2  0x00007f380473d80c in RadeonCompositeCP (pDst=0x4aad820, srcX=0, srcY=0, maskX=0, maskY=7, dstX=0, dstY=0, width=1146, height=916) at radeon_exa_render.c:2426
#3  0x00007f38039f0b70 in exaTryDriverComposite (op=<value optimized out>, pSrc=<value optimized out>, pMask=<value optimized out>, pDst=<value optimized out>, 
    xSrc=<value optimized out>, ySrc=<value optimized out>, xMask=<value optimized out>, yMask=<value optimized out>, xDst=<value optimized out>, 
    yDst=<value optimized out>, width=<value optimized out>, height=<value optimized out>) at exa_render.c:763
#4  0x00007f38039f2438 in exaComposite (op=176 '\260', pSrc=0x45637c0, pMask=0x0, pDst=0x34018a0, xSrc=0, ySrc=<value optimized out>, xMask=0, yMask=0, xDst=0, 
    yDst=<value optimized out>, width=1146, height=916) at exa_render.c:967
#5  0x00000000004d5e97 in damageComposite (op=176 '\260', pSrc=<value optimized out>, pMask=<value optimized out>, pDst=0x34018a0, xSrc=0, ySrc=480, 
    xMask=<value optimized out>, yMask=<value optimized out>, xDst=0, yDst=0, width=1146, height=916) at damage.c:643
#6  0x00000000004cf335 in ProcRenderComposite (client=0x2dc1cb0) at render.c:723
#7  0x000000000042dbf4 in Dispatch () at dispatch.c:445
#8  0x0000000000421d3a in main (argc=<value optimized out>, argv=0x1, envp=<value optimized out>) at main.c:285