This here is with 2.6.35-12.17 and "set gfxpayload=keep". At first boot I get some garbage when X starts (on both my monitors) but after a reboot X starts up fine. Here is some kernel log from the first unsuccessful boot: Jul 30 09:19:48 vorlon kernel: [ 21.819264] ------------[ cut here ]------------ Jul 30 09:19:48 vorlon kernel: [ 21.819288] WARNING: at /build/buildd/linux-2.6.35/drivers/gpu/drm/radeon/radeon_fence.c:235 radeon_fence_wait+0x365/0x3d0 [radeon]() Jul 30 09:19:48 vorlon kernel: [ 21.819290] Hardware name: M56S-S3 Jul 30 09:19:48 vorlon kernel: [ 21.819292] GPU lockup (waiting for 0x00000003 last fence id 0x00000001) Jul 30 09:19:48 vorlon kernel: [ 21.819293] Modules linked in: snd_hda_codec_atihdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec radeon snd_hwdep snd_seq_midi snd_pcm ttm snd_rawmidi drm_kms_helper snd_seq_midi_event snd_seq snd_timer snd_seq_device psmouse drm snd serio_raw i2c_algo_bit k8temp i2c_nforce2 soundcore ppdev edac_core edac_mce_amd snd_page_alloc parport_pc lp parport raid10 raid456 async_pq async_xor xor async_memcpy async_raid6_recov raid6_pq async_tx raid1 raid0 multipath ahci firewire_ohci firewire_core crc_itu_t linear forcedeth pata_amd libahci Jul 30 09:19:48 vorlon kernel: [ 21.819329] Pid: 1086, comm: Xorg Tainted: G D 2.6.35-12-generic #17-Ubuntu Jul 30 09:19:48 vorlon kernel: [ 21.819331] Call Trace: Jul 30 09:19:48 vorlon kernel: [ 21.819338] [] warn_slowpath_common+0x7f/0xc0 Jul 30 09:19:48 vorlon kernel: [ 21.819341] [] warn_slowpath_fmt+0x46/0x50 Jul 30 09:19:48 vorlon kernel: [ 21.819354] [] radeon_fence_wait+0x365/0x3d0 [radeon] Jul 30 09:19:48 vorlon kernel: [ 21.819358] [] ? autoremove_wake_function+0x0/0x40 Jul 30 09:19:48 vorlon kernel: [ 21.819370] [] radeon_sync_obj_wait+0x11/0x20 [radeon] Jul 30 09:19:48 vorlon kernel: [ 21.819378] [] ttm_bo_wait+0x103/0x1c0 [ttm] Jul 30 09:19:48 vorlon kernel: [ 21.819392] [] radeon_gem_wait_idle_ioctl+0x97/0x140 [radeon] Jul 30 09:19:48 vorlon kernel: [ 21.819407] [] drm_ioctl+0x34a/0x4c0 [drm] Jul 30 09:19:48 vorlon kernel: [ 21.819421] [] ? radeon_gem_wait_idle_ioctl+0x0/0x140 [radeon] Jul 30 09:19:48 vorlon kernel: [ 21.819425] [] ? _raw_spin_lock_irq+0x15/0x20 Jul 30 09:19:48 vorlon kernel: [ 21.819430] [] ? handle_signal+0x131/0x280 Jul 30 09:19:48 vorlon kernel: [ 21.819432] [] ? do_signal+0x81/0x1a0 Jul 30 09:19:48 vorlon kernel: [ 21.819436] [] vfs_ioctl+0x3d/0xd0 Jul 30 09:19:48 vorlon kernel: [ 21.819438] [] do_vfs_ioctl+0x81/0x340 Jul 30 09:19:48 vorlon kernel: [ 21.819441] [] ? sys_rt_sigreturn+0x235/0x250 Jul 30 09:19:48 vorlon kernel: [ 21.819444] [] sys_ioctl+0x81/0xa0 Jul 30 09:19:48 vorlon kernel: [ 21.819447] [] system_call_fastpath+0x16/0x1b Jul 30 09:19:48 vorlon kernel: [ 21.819449] ---[ end trace d3627d239cbe15f9 ]--- Jul 30 09:19:48 vorlon kernel: [ 21.819456] [drm] Disabling audio support Jul 30 09:19:48 vorlon kernel: [ 21.820513] radeon 0000:02:00.0: GPU softreset Jul 30 09:19:48 vorlon kernel: [ 21.820516] radeon 0000:02:00.0: R_008010_GRBM_STATUS=0xA0003030 Jul 30 09:19:48 vorlon kernel: [ 21.820518] radeon 0000:02:00.0: R_008014_GRBM_STATUS2=0x00000003 Jul 30 09:19:48 vorlon kernel: [ 21.820521] radeon 0000:02:00.0: R_000E50_SRBM_STATUS=0x200208C0 Jul 30 09:19:48 vorlon kernel: [ 21.968630] radeon 0000:02:00.0: Wait for MC idle timedout ! Jul 30 09:19:48 vorlon kernel: [ 21.968633] radeon 0000:02:00.0: R_008020_GRBM_SOFT_RESET=0x00007FEE Jul 30 09:19:48 vorlon kernel: [ 21.983646] radeon 0000:02:00.0: R_008020_GRBM_SOFT_RESET=0x00000001 Jul 30 09:19:48 vorlon kernel: [ 21.999644] radeon 0000:02:00.0: R_008010_GRBM_STATUS=0x00003030 Jul 30 09:19:48 vorlon kernel: [ 21.999647] radeon 0000:02:00.0: R_008014_GRBM_STATUS2=0x00000003 Jul 30 09:19:48 vorlon kernel: [ 21.999649] radeon 0000:02:00.0: R_000E50_SRBM_STATUS=0x200208C0 Jul 30 09:19:48 vorlon kernel: [ 22.000665] radeon 0000:02:00.0: GPU reset succeed Jul 30 09:19:48 vorlon kernel: [ 22.002215] [drm] Clocks initialized ! Jul 30 09:19:49 vorlon kernel: [ 22.150225] radeon 0000:02:00.0: Wait for MC idle timedout ! Jul 30 09:19:49 vorlon kernel: [ 22.298149] radeon 0000:02:00.0: Wait for MC idle timedout ! Jul 30 09:19:49 vorlon kernel: [ 22.481493] [drm:r600_ring_test] *ERROR* radeon: ring test failed (scratch(0x8504)=0xCAFEDEAD) Jul 30 09:19:49 vorlon kernel: [ 22.481498] [drm:r600_resume] *ERROR* r600 startup failed on resume And after that many lines: Jul 30 09:20:00 vorlon kernel: [ 33.458963] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(0). Jul 30 09:20:00 vorlon kernel: [ 33.458965] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459062] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(1). Jul 30 09:20:00 vorlon kernel: [ 33.459064] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459161] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(2). Jul 30 09:20:00 vorlon kernel: [ 33.459163] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459260] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(3). Jul 30 09:20:00 vorlon kernel: [ 33.459262] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459357] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(4). Jul 30 09:20:00 vorlon kernel: [ 33.459359] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459460] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(5). Jul 30 09:20:00 vorlon kernel: [ 33.459462] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459559] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(6). Jul 30 09:20:00 vorlon kernel: [ 33.459561] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459656] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(7). Jul 30 09:20:00 vorlon kernel: [ 33.459658] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459753] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(8). Jul 30 09:20:00 vorlon kernel: [ 33.459755] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459852] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(9). Jul 30 09:20:00 vorlon kernel: [ 33.459854] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.459948] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(10). Jul 30 09:20:00 vorlon kernel: [ 33.459950] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.460073] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(11). Jul 30 09:20:00 vorlon kernel: [ 33.460076] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.460180] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(12). Jul 30 09:20:00 vorlon kernel: [ 33.460182] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.460279] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(13). Jul 30 09:20:00 vorlon kernel: [ 33.460280] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.460376] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(14). Jul 30 09:20:00 vorlon kernel: [ 33.460378] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! Jul 30 09:20:00 vorlon kernel: [ 33.460472] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(15). Jul 30 09:20:00 vorlon kernel: [ 33.460474] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! [ repeated till I decided to reboot ] And in both cases (the unsuccessful and the succesful boot) I have also a crash from plymouthd: Jul 30 09:21:13 vorlon kernel: [ 13.495193] BUG: unable to handle kernel NULL pointer dereference at (null) Jul 30 09:21:13 vorlon kernel: [ 13.495199] IP: [] __mutex_lock_slowpath+0xd2/0x190 Jul 30 09:21:13 vorlon kernel: [ 13.495206] PGD 11b6fb067 PUD 11b6fd067 PMD 0 Jul 30 09:21:13 vorlon kernel: [ 13.495209] Oops: 0002 [#1] SMP Jul 30 09:21:13 vorlon kernel: [ 13.495211] last sysfs file: /sys/devices/virtual/block/md1/uevent Jul 30 09:21:13 vorlon kernel: [ 13.495214] CPU 0 Jul 30 09:21:13 vorlon kernel: [ 13.495215] Modules linked in: snd_hda_codec_atihdmi snd_hda_codec_realtek radeon snd_seq_midi snd_hda_intel snd_rawmidi ttm snd_hda_codec snd_hwdep snd_pcm snd_seq_midi_event ppdev snd_seq snd_timer snd_seq_device parport_pc k8temp snd drm_kms_helper soundcore snd_page_alloc drm i2c_nforce2 psmouse serio_raw edac_core i2c_algo_bit edac_mce_amd lp parport raid10 raid456 async_pq async_xor xor async_memcpy async_raid6_recov raid6_pq async_tx raid1 raid0 multipath ahci firewire_ohci firewire_core crc_itu_t linear pata_amd forcedeth libahci Jul 30 09:21:13 vorlon kernel: [ 13.495243] Jul 30 09:21:13 vorlon kernel: [ 13.495246] Pid: 378, comm: plymouthd Not tainted 2.6.35-12-generic #17-Ubuntu GA-M56S-S3/M56S-S3 Jul 30 09:21:13 vorlon kernel: [ 13.495248] RIP: 0010:[] [] __mutex_lock_slowpath+0xd2/0x190 Jul 30 09:21:13 vorlon kernel: [ 13.495252] RSP: 0018:ffff8801174f5e18 EFLAGS: 00010246 Jul 30 09:21:13 vorlon kernel: [ 13.495254] RAX: 0000000000000000 RBX: ffff88011afac008 RCX: 00000000ffffffff Jul 30 09:21:13 vorlon kernel: [ 13.495256] RDX: ffff8801174f5e28 RSI: 00000000ffffffff RDI: ffff88011afac00c Jul 30 09:21:13 vorlon kernel: [ 13.495258] RBP: ffff8801174f5e78 R08: 0000000000000000 R09: 0000000000000000 Jul 30 09:21:13 vorlon kernel: [ 13.495260] R10: 00007fff1e5e5f20 R11: 0000000000000246 R12: ffff880117782dc0 Jul 30 09:21:13 vorlon kernel: [ 13.495262] R13: ffff88011afac00c R14: 00000000ffffffff R15: ffff88011afac010 Jul 30 09:21:13 vorlon kernel: [ 13.495264] FS: 00007f24ccdc2700(0000) GS:ffff880001e00000(0000) knlGS:0000000000000000 Jul 30 09:21:13 vorlon kernel: [ 13.495266] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b Jul 30 09:21:13 vorlon kernel: [ 13.495268] CR2: 0000000000000000 CR3: 000000011b6ec000 CR4: 00000000000006f0 Jul 30 09:21:13 vorlon kernel: [ 13.495270] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jul 30 09:21:13 vorlon kernel: [ 13.495272] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Jul 30 09:21:13 vorlon kernel: [ 13.495274] Process plymouthd (pid: 378, threadinfo ffff8801174f4000, task ffff880117782dc0) Jul 30 09:21:13 vorlon kernel: [ 13.495276] Stack: Jul 30 09:21:13 vorlon kernel: [ 13.495277] ffff8801174f5fd8 ffff880117782dc0 ffff88011afac010 0000000000000000 Jul 30 09:21:13 vorlon kernel: [ 13.495280] <0> ffff8801174f5e88 ffffffff8112dfb4 ffff8801174f5e68 ffff88011afac008 Jul 30 09:21:13 vorlon kernel: [ 13.495284] <0> ffff88011afac008 ffff88011afa2fb0 ffff88011fbb96c0 ffff88011b620d00 Jul 30 09:21:13 vorlon kernel: [ 13.495287] Call Trace: Jul 30 09:21:13 vorlon kernel: [ 13.495293] [] ? free_pages_and_swap_cache+0xb4/0xe0 Jul 30 09:21:13 vorlon kernel: [ 13.495295] [] mutex_lock+0x2b/0x50 Jul 30 09:21:13 vorlon kernel: [ 13.495300] [] fb_release+0x29/0x70 Jul 30 09:21:13 vorlon kernel: [ 13.495303] [] __fput+0xf5/0x210 Jul 30 09:21:13 vorlon kernel: [ 13.495305] [] fput+0x25/0x30 Jul 30 09:21:13 vorlon kernel: [ 13.495309] [] filp_close+0x5d/0x90 Jul 30 09:21:13 vorlon kernel: [ 13.495312] [] sys_close+0xb7/0x120 Jul 30 09:21:13 vorlon kernel: [ 13.495316] [] system_call_fastpath+0x16/0x1b Jul 30 09:21:13 vorlon kernel: [ 13.495317] Code: 00 4c 8d 6b 04 4c 8d 7b 08 41 be ff ff ff ff 4c 89 ef e8 22 14 00 00 48 8b 43 10 48 8d 55 b0 48 89 53 10 4c 89 7d b0 48 89 45 b8 <48> 89 10 44 89 f0 4c 89 65 c0 87 03 83 f8 01 75 24 eb 2c 0f 1f Jul 30 09:21:13 vorlon kernel: [ 13.495341] RIP [] __mutex_lock_slowpath+0xd2/0x190 Jul 30 09:21:13 vorlon kernel: [ 13.495343] RSP Jul 30 09:21:13 vorlon kernel: [ 13.495345] CR2: 0000000000000000 Jul 30 09:21:13 vorlon kernel: [ 13.495347] ---[ end trace b121fe4132eae870 ]---