BUG: unable to handle kernel paging request at ffffc90001c00000
IP: [<ffffffffa025bb93>] r600_ioctl_wait_idle+0x43/0xb0 [radeon]
PGD 12fc15067 PUD 12fc16067 PMD 1284af067 PTE 0
Oops: 0000 [#6] SMP 
last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/0000:02:00.0/boot_vga
CPU 0 
Modules linked in: parport_pc ppdev binfmt_misc snd_hda_codec_realtek snd_hda_codec_atihdmi radeon snd_seq_midi snd_hda_intel snd_rawmidi snd_hda_codec snd_hwdep snd_seq_midi_event snd_seq ttm snd_pcm snd_seq_device drm_kms_helper snd_timer joydev amd64_edac_mod snd drm psmouse edac_core soundcore lp wacom serio_raw i2c_algo_bit k8temp snd_page_alloc edac_mce_amd shpchp i2c_viapro parport raid10 raid456 async_pq async_xor xor async_memcpy async_raid6_recov raid6_pq async_tx raid1 raid0 usbhid multipath hid linear atl1 sata_via mii pata_via

Pid: 1248, comm: Xorg Tainted: G      D W   2.6.35-22-generic #33-Ubuntu M2V/System Product Name
RIP: 0010:[<ffffffffa025bb93>]  [<ffffffffa025bb93>] r600_ioctl_wait_idle+0x43/0xb0 [radeon]
RSP: 0018:ffff88011ef9dd38  EFLAGS: 00010246
RAX: ffffc90001c00000 RBX: ffff88012012e800 RCX: ffffc900010e0000
RDX: 0000000000000000 RSI: ffff88012012e800 RDI: ffff88011f8d0000
RBP: ffff88011ef9dd38 R08: 0000000000000000 R09: ffffffffa0234cc0
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: ffff88012004e840 R14: ffff88012012e878 R15: ffff88012012e8d8
FS:  00007f84203e4840(0000) GS:ffff880001e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90001c00000 CR3: 000000011eecf000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process Xorg (pid: 1248, threadinfo ffff88011ef9c000, task ffff88011d4144a0)
Stack:
 ffff88011ef9dd78 ffffffffa0234d8b ffff88011f0e8228 ffff88011f0d7a80
<0> ffff880127bad800 0000000000000064 00000000c0086464 0000000002520400
<0> ffff88011ef9dea8 ffffffffa012b433 ffff880100000064 000000000000e200
Call Trace:
 [<ffffffffa0234d8b>] radeon_gem_wait_idle_ioctl+0xcb/0x140 [radeon]
 [<ffffffffa012b433>] drm_ioctl+0x463/0x520 [drm]
 [<ffffffffa0234cc0>] ? radeon_gem_wait_idle_ioctl+0x0/0x140 [radeon]
 [<ffffffff8116295d>] vfs_ioctl+0x3d/0xd0
 [<ffffffff81163231>] do_vfs_ioctl+0x81/0x340
 [<ffffffff81163571>] sys_ioctl+0x81/0xa0
 [<ffffffff8100a0f2>] system_call_fastpath+0x16/0x1b
Code: 00 00 00 34 2f 00 00 48 8b 87 60 03 00 00 77 58 48 8b 8f c8 00 00 00 ba 34 2f 00 00 89 11 48 8b 8f c8 00 00 00 66 31 d2 89 51 04 <8b> 00 c9 c3 eb 07 90 90 90 90 90 90 90 48 81 bf c0 00 00 00 80 
RIP  [<ffffffffa025bb93>] r600_ioctl_wait_idle+0x43/0xb0 [radeon]
 RSP <ffff88011ef9dd38>
CR2: ffffc90001c00000
---[ end trace dce991a0ec050d46 ]---