Backtrace:                                                                                                                                                                                                                                       [27/2830]
 [<00000000401f9484>] insert_pfn+0x16c/0x1c0
 [<00000000401f99dc>] vm_insert_mixed+0x11c/0x150
 [<000000000816dcc0>] ttm_bo_vm_fault+0x278/0x4e8 [ttm]
 [<00000000104d8658>] radeon_ttm_fault+0x78/0xd0 [radeon]
 [<00000000401f1c84>] __do_fault+0xac/0xaf0
 [<00000000401f6a14>] handle_pte_fault+0xb4/0xea0
 [<00000000401f8104>] handle_mm_fault+0x104/0x1b8
 [<00000000401162b0>] do_page_fault+0x2b8/0x530
 [<000000004011975c>] handle_interruption+0x264/0xb58


Bad Address (null pointer deref?): Code=15 regs=000000007d0409f0 (Addr=0000000043ea67c0)
CPU: 0 PID: 3051 Comm: Xorg Not tainted 3.10.0-rc6-64bit-c3000+ #12
task: 000000007d10e1c0 ti: 000000007d040000 task.ti: 000000007d040000

     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001000000010000001111 Not tainted
r00-03  000000e00804040f 0000000040a54300 00000000401f9484 000000007d040950
r04-07  0000000040a03b00 00000000408782a0 037fffffff3d27c0 0000000044ad4000
r08-11  ffffffffc8548000 ffffffffc8548b03 000000007d106220 000000000800000f
r12-15  000000007d0407d0 0000000000000010 0000000000000000 000000007d8a86f8
r16-19  0000000008161000 0000000000000006 00000000002063fc 000f000000000000
r20-23  0000000000000000 0000000000000029 0000000000000000 0000000000000b03                                                                                                                                                                                   [4/2830]
r24-27  000000007d106220 0000000045c44000 000000007d047600 0000000040a03b00
r28-31  00000000408782a0 000000007d040920 000000007d0409f0 006fffffffe7a4f8
sr00-03  000000000000e800 000000000000e800 0000000000000000 000000000000e800
sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

IASQ: 0000000000000000 0000000000000000 IAOQ: 000000004011707c 0000000040117080
 IIR: 0cc700dc    ISR: 0000000003800000  IOR: 0000000043ea67c0
 CPU:        0   CR30: 000000007d040000 CR31: ffffffffffffffff
 ORIG_R28: 000000007d040bd0
 IAOQ[0]: update_mmu_cache+0x84/0x2f0
 IAOQ[1]: update_mmu_cache+0x88/0x2f0
 RP(r2): insert_pfn+0x16c/0x1c0
Backtrace:
 [<00000000401f9484>] insert_pfn+0x16c/0x1c0
 [<00000000401f99dc>] vm_insert_mixed+0x11c/0x150
 [<000000000816dcc0>] ttm_bo_vm_fault+0x278/0x4e8 [ttm]
 [<00000000104d8658>] radeon_ttm_fault+0x78/0xd0 [radeon]
 [<00000000401f1c84>] __do_fault+0xac/0xaf0
 [<00000000401f6a14>] handle_pte_fault+0xb4/0xea0
 [<00000000401f8104>] handle_mm_fault+0x104/0x1b8
 [<00000000401162b0>] do_page_fault+0x2b8/0x530
 [<000000004011975c>] handle_interruption+0x264/0xb58

Kernel panic - not syncing: Bad Address (null pointer deref?)
drm_kms_helper: panic occurred, switching back to text console