Comment 11 for bug 757141

i keep seeing this as well.

stacktrace looks like this:

May 12 12:53:54 kasperl kernel: [15845.850266] radeon 0000:0e:00.0: GPU lockup CP stall for more than 10000msec
May 12 12:53:54 kasperl kernel: [15845.850271] ------------[ cut here ]------------
May 12 12:53:54 kasperl kernel: [15845.850319] WARNING: at /build/buildd/linux-2.6.38/drivers/gpu/drm/radeon/radeon_fence.c:248 radeon_fence_wait+0x36f/0x3e0 [radeon]()
May 12 12:53:54 kasperl kernel: [15845.850321] Hardware name: MacPro1,1
May 12 12:53:54 kasperl kernel: [15845.850322] GPU lockup (waiting for 0x0002D4AA last fence id 0x0002D4A9)
May 12 12:53:54 kasperl kernel: [15845.850324] Modules linked in: binfmt_misc sco bnep l2cap parport_pc ppdev btusb bluetooth snd_hda_codec_realtek lm63 snd_hda_intel snd_hda
_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi radeon applesmc lib80211_crypt_tkip input_polldev snd_seq_midi_event ttm wl(P) drm_kms_helper snd_seq snd_timer snd_seq_devi
ce i5000_edac edac_core i5k_amb ioatdma drm lib80211 dca i2c_algo_bit snd soundcore snd_page_alloc shpchp lp parport usbhid hid firewire_ohci firewire_core crc_itu_t e1000e
May 12 12:53:54 kasperl kernel: [15845.850353] Pid: 903, comm: Xorg Tainted: P 2.6.38-8-generic #42-Ubuntu
May 12 12:53:54 kasperl kernel: [15845.850355] Call Trace:
May 12 12:53:54 kasperl kernel: [15845.850362] [<ffffffff81065cef>] ? warn_slowpath_common+0x7f/0xc0
May 12 12:53:54 kasperl kernel: [15845.850365] [<ffffffff81065de6>] ? warn_slowpath_fmt+0x46/0x50
May 12 12:53:54 kasperl kernel: [15845.850375] [<ffffffffa03dc6df>] ? radeon_fence_wait+0x36f/0x3e0 [radeon]
May 12 12:53:54 kasperl kernel: [15845.850379] [<ffffffff81087f30>] ? autoremove_wake_function+0x0/0x40
May 12 12:53:54 kasperl kernel: [15845.850391] [<ffffffffa03f607d>] ? radeon_ib_get+0x12d/0x1e0 [radeon]
May 12 12:53:54 kasperl kernel: [15845.850402] [<ffffffffa03f7a4e>] ? radeon_cs_ioctl+0x8e/0x1e0 [radeon]
May 12 12:53:54 kasperl kernel: [15845.850415] [<ffffffffa00ee384>] ? drm_ioctl+0x3e4/0x4c0 [drm]
May 12 12:53:54 kasperl kernel: [15845.850418] [<ffffffff81134790>] ? __remove_shared_vm_struct.clone.30+0x40/0x60
May 12 12:53:54 kasperl kernel: [15845.850429] [<ffffffffa03f79c0>] ? radeon_cs_ioctl+0x0/0x1e0 [radeon]
May 12 12:53:54 kasperl kernel: [15845.850433] [<ffffffff812e2055>] ? timerqueue_del+0x35/0x90
May 12 12:53:54 kasperl kernel: [15845.850436] [<ffffffff8108b89b>] ? __remove_hrtimer+0x3b/0x80
May 12 12:53:54 kasperl kernel: [15845.850439] [<ffffffff8108bc5c>] ? hrtimer_try_to_cancel+0x4c/0xe0
May 12 12:53:54 kasperl kernel: [15845.850442] [<ffffffff8117648f>] ? do_vfs_ioctl+0x8f/0x360
May 12 12:53:54 kasperl kernel: [15845.850445] [<ffffffff8106b4b4>] ? sys_setitimer+0x64/0xe0
May 12 12:53:54 kasperl kernel: [15845.850448] [<ffffffff811767f1>] ? sys_ioctl+0x91/0xa0
May 12 12:53:54 kasperl kernel: [15845.850451] [<ffffffff8100c002>] ? system_call_fastpath+0x16/0x1b
May 12 12:53:54 ka

graphics card is a radeon R580 / X1900 XT. i'm getting these freezes only since upgrading to natty, no issues with maverick. also, i cant use unity3d; if i try, monitor just turns black and goes to sleep.