------------[ cut here ]------------
WARNING: at /build/buildd/linux-2.6.38/drivers/gpu/drm/radeon/radeon_fence.c:248 radeon_fence_wait+0x2ea/0x360 [radeon]()
Hardware name: RV410/RV510                 
GPU lockup (waiting for 0x002D1747 last fence id 0x002D173B)
Modules linked in: btrfs zlib_deflate libcrc32c ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs exportfs reiserfs binfmt_misc cryptd aes_i586 aes_generic parport_pc ppdev snd_hda_codec_realtek snd_hda_intel snd_hda_codec radeon snd_hwdep snd_pcm snd_seq_midi arc4 snd_rawmidi snd_seq_midi_event ttm drm_kms_helper drm psmouse i2c_algo_bit serio_raw snd_seq uvcvideo videodev video lp snd_timer ath9k mac80211 snd_seq_device ath9k_common parport snd ath9k_hw ath soundcore snd_page_alloc cfg80211 ahci libahci sky2
Pid: 31083, comm: Xorg Not tainted 2.6.38-8-generic-pae #41-Ubuntu
Call Trace:
 [<c1058ce2>] ? warn_slowpath_common+0x72/0xa0
 [<f87dbf3a>] ? radeon_fence_wait+0x2ea/0x360 [radeon]
 [<f87dbf3a>] ? radeon_fence_wait+0x2ea/0x360 [radeon]
 [<c1058db3>] ? warn_slowpath_fmt+0x33/0x40
 [<f87dbf3a>] ? radeon_fence_wait+0x2ea/0x360 [radeon]
 [<c1076c70>] ? autoremove_wake_function+0x0/0x50
 [<f87dc7c1>] ? radeon_sync_obj_wait+0x11/0x20 [radeon]
 [<f862b719>] ? ttm_bo_wait+0xd9/0x170 [ttm]
 [<f87f48c2>] ? radeon_gem_wait_idle_ioctl+0x82/0xe0 [radeon]
 [<f8659db1>] ? drm_ioctl+0x1e1/0x470 [drm]
 [<f87f4840>] ? radeon_gem_wait_idle_ioctl+0x0/0xe0 [radeon]
 [<c1013b8b>] ? restore_i387_xstate+0x17b/0x210
 [<f8659bd0>] ? drm_ioctl+0x0/0x470 [drm]
 [<c1141ecb>] ? do_vfs_ioctl+0x7b/0x2e0
 [<c1009cde>] ? restore_sigcontext+0xbe/0xe0
 [<c11421b7>] ? sys_ioctl+0x87/0x90
 [<c100ab5f>] ? sysenter_do_call+0x12/0x28
---[ end trace 738fe2861db4bcf7 ]---