I recently installed Ubuntu 16.04 on my personal notebook (Dell Inspiron 5548) and everytime I try to logout from any user account, I get a Kernel BUG ("Oops" message) related to amdgpu.
I tried both upgrading from 14 LTS and full installation using an 16.04 image on usb drive. I also have been using Ubuntu 15 in my computer for quite a while without any similar problems.
I have read that it might be related to the new amd graphic cards replacing fglrx and that only brand new graphic cards would be supported. However, I have installed Ubuntu 16 on Dell Studio 1458 (can't remember the graphic card now, but it is also Radeon) and it worked like a charm.
The BUG report follows below. Does any one knows some fix for this?
EDIT: my graphics card is AMD Radeon™ HD R7 M265.
May 3 10:57:58 ubuntu-5548 kernel: [ 329.916153] [drm] PCIE GART of 2048M enabled (table at 0x0000000000040000).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155529] [drm] ring test on 0 succeeded in 15 usecs
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155722] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 1 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155736] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 2 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155747] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 3 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155757] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 4 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155766] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 5 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155775] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 6 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155784] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 7 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155793] [drm:gfx_v8_0_ring_test_ring [amdgpu]] *ERROR* amdgpu: cp failed to lock ring 8 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155821] [drm] ring test on 9 succeeded in 7 usecs
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155837] [drm:sdma_v2_4_ring_test_ring [amdgpu]] *ERROR* amdgpu: dma failed to lock ring 10 (-2).
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155844] [drm:amdgpu_resume [amdgpu]] *ERROR* resume 5 failed -2
May 3 10:57:58 ubuntu-5548 kernel: [ 330.155852] [drm:amdgpu_resume_kms [amdgpu]] *ERROR* amdgpu_resume failed (-2).
May 3 10:57:58 ubuntu-5548 acpid: client 984[0:0] has disconnected
May 3 10:57:58 ubuntu-5548 acpid: client connected from 3312[0:0]
May 3 10:57:58 ubuntu-5548 acpid: 1 client rule loaded
May 3 10:57:59 ubuntu-5548 kernel: [ 330.329604] BUG: unable to handle kernel NULL pointer dereference at 0000000000000248
May 3 10:57:59 ubuntu-5548 kernel: [ 330.329631] IP: [<ffffffffc0348ea2>] amdgpu_vm_grab_id+0x122/0x310 [amdgpu]
May 3 10:57:59 ubuntu-5548 kernel: [ 330.329667] PGD 0
May 3 10:57:59 ubuntu-5548 kernel: [ 330.329674] Oops: 0000 [#1] SMP
May 3 10:57:59 ubuntu-5548 kernel: [ 330.329686] Modules linked in: drbg ansi_cprng ctr ccm rfcomm bnep rtsx_usb_sdmmc rtsx_usb_ms memstick rtsx_usb nls_iso8859_1 intel_rapl x86_pkg_temp_thermal intel_powerclamp arc4 coretemp kvm_intel kvm iwlmvm mac80211 irqbypass crct10dif_pclmul dell_wmi crc32_pclmul dell_laptop sparse_keymap dcdbas snd_hda_codec_hdmi dell_smm_hwmon aesni_intel aes_x86_64 lrw gf128mul glue_helper iwlwifi ablk_helper cryptd dell_led btusb btrtl btbcm input_leds btintel serio_raw snd_hda_codec_realtek bluetooth hid_multitouch snd_hda_codec_generic joydev cfg80211 snd_soc_rt5640 snd_hda_intel snd_soc_ssm4567 snd_soc_rl6231 snd_hda_codec lpc_ich elan_i2c snd_soc_core snd_hda_core snd_hwdep snd_compress ac97_bus snd_pcm_dmaengine snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd dw_dmac dw_dmac_core soundcore dell_rbtn snd_soc_sst_acpi shpchp mei_me i2c_designware_platform 8250_dw mei spi_pxa2xx_platform i2c_designware_core acpi_pad mac_hid uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_core v4l2_common videodev media parport_pc ppdev lp parport autofs4 hid_generic usbhid amdkfd amd_iommu_v2 amdgpu i915 ttm psmouse i2c_algo_bit drm_kms_helper syscopyarea ahci sysfillrect libahci sysimgblt fb_sys_fops r8169 drm mii wmi video i2c_hid hid sdhci_acpi sdhci fjes
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330101] CPU: 0 PID: 163 Comm: gfx Not tainted 4.4.0-21-generic #37-Ubuntu
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330120] Hardware name: Dell Inc. Inspiron 5548/0YDTG3, BIOS A04 05/15/2015
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330140] task: ffff8804460e44c0 ti: ffff8804448dc000 task.ti: ffff8804448dc000
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330160] RIP: 0010:[<ffffffffc0348ea2>] [<ffffffffc0348ea2>] amdgpu_vm_grab_id+0x122/0x310 [amdgpu]
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330197] RSP: 0018:ffff8804448dfce0 EFLAGS: 00010246
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330211] RAX: 0000000000000000 RBX: ffff880445530000 RCX: ffff88008eefd400
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330230] RDX: ffffffff81ef3cc0 RSI: ffff880445532d78 RDI: ffff880449cc3000
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330249] RBP: ffff8804448dfdb0 R08: ffff88008eefd400 R09: 000000018080004d
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330268] R10: ffff8803f30ee020 R11: 0000000000000004 R12: ffff880445532d78
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330286] R13: ffff880449cc3000 R14: ffff880445530838 R15: 0000000000000001
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330305] FS: 0000000000000000(0000) GS:ffff88045ec00000(0000) knlGS:0000000000000000
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330327] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330342] CR2: 0000000000000248 CR3: 0000000002e0a000 CR4: 00000000003406f0
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330361] Stack:
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330367] ffff88042a99dc48 0000000000000000 ffff88008eefd400 0000000000000000
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330390] 0000000000000000 0000000000000000 0000000000000000 0000000000000000
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330412] 0000000000000000 0000000000000000 0000000000000000 0000000000000000
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330435] Call Trace:
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330454] [<ffffffffc034ace0>] amdgpu_ib_schedule+0x90/0x390 [amdgpu]
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330487] [<ffffffffc03873b6>] amdgpu_sched_run_job+0x36/0x140 [amdgpu]
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330519] [<ffffffffc0386bcf>] amd_sched_main+0x23f/0x400 [amdgpu]
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330538] [<ffffffff810c3a10>] ? wake_atomic_t_function+0x60/0x60
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330567] [<ffffffffc0386990>] ? amd_sched_entity_wakeup+0x70/0x70 [amdgpu]
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330587] [<ffffffff810a0528>] kthread+0xd8/0xf0
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330601] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330621] [<ffffffff8182488f>] ret_from_fork+0x3f/0x70
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330636] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330653] Code: c0 44 89 bc 85 48 ff ff ff 41 83 c7 01 44 39 bb 1c 09 00 00 76 4f 49 83 c6 10 4d 8b 6e f0 4d 85 ed 74 66 4c 89 ef e8 fe 2e ff ff <8b> b8 48 02 00 00 48 8b b4 fd 50 ff ff ff 48 85 f6 74 b2 41 8b
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330757] RIP [<ffffffffc0348ea2>] amdgpu_vm_grab_id+0x122/0x310 [amdgpu]
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330788] RSP <ffff8804448dfce0>
May 3 10:57:59 ubuntu-5548 kernel: [ 330.330797] CR2: 0000000000000248
May 3 10:57:59 ubuntu-5548 kernel: [ 330.337194] ---[ end trace f4393c5763eacaf5 ]---