Sorry, I don't know the proper way for this. I've never seen this problem before upgrading to Ubuntu 16.10. I've tried the stock kernel and the newest "stable" (4.8.4) and both show this problem. Unfortunately I don't know how much information I can get, since it locks me up pretty badly. My setup has not changed: HP EliteBook 9480m, latest bios (not changed), Intel video HP Slim dock (2013 model) Two monitors (DVI monitors, connected to the two DisplayPort ports on the dock via passive DVI 2 DP adapters.. Also tried to move one to VGA port, didn't make a difference) I had some issues with USB3 support in linux on this box (with older kernels) and I tried turning USB3 off in BIOS, but didn't make any difference. THe below shows what happens when I undock: ... [Oct26 11:30] usb 1-1.1: clear tt 2 (0060) error -71 [ +0.008164] usb 1-1.1: clear tt 4 (0080) error -71 [ +0.004248] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004256] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004252] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004250] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004246] usb 1-1.1-port2: cannot reset (err = -71) [ +0.000007] usb 1-1.1-port2: Cannot enable. Maybe the USB cable is bad? [ +0.004240] usb 1-1.1-port2: cannot disable (err = -71) [ +0.004248] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004261] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004253] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004247] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004244] usb 1-1.1-port2: cannot reset (err = -71) [ +0.000009] usb 1-1.1-port2: Cannot enable. Maybe the USB cable is bad? [ +0.004239] usb 1-1.1-port2: cannot disable (err = -71) [ +0.004250] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004295] usb 1-1.1-port2: cannot reset (err = -71) [ +0.004208] usb 1-1.1-port2: cannot reset (err = -71) [ +0.001092] BUG: unable to handle kernel paging request at fffffffffffffffe [ +0.000093] IP: [<ffffffff8d17fef7>] device_del+0x17/0x260 [ +0.000072] PGD 40ba09067 PUD 40ba0b067 PMD 0 [ +0.000057] Oops: 0000 [#1] SMP [ +0.000034] Modules linked in: iptable_filter ip6table_filter ip6_tables ccm cmac bnep arc4 hp_wmi sparse_keymap intel_rapl nls_iso8859_1 x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_hda_codec_hdmi kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw glue_helper ablk_helper cryptd snd_hda_codec_realtek intel_cstate snd_hda_codec_generic intel_rapl_perf iwlmvm snd_hda_intel snd_hda_codec mac80211 snd_hda_core snd_hwdep serio_raw snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi iwlwifi btusb btrtl joydev btbcm btintel input_leds bluetooth snd_seq cfg80211 snd_seq_device snd_timer rtsx_pci_ms memstick snd lpc_ich soundcore mei_me shpchp mei hp_accel lis3lv02d input_polldev mac_hid hp_wireless tpm_infineon parport_pc ppdev lp parport ip_tables [ +0.000960] x_tables autofs4 hid_plantronics hid_generic usbhid hid rtsx_pci_sdmmc i915 psmouse i2c_algo_bit ahci drm_kms_helper libahci syscopyarea e1000e sysfillrect sysimgblt fb_sys_fops rtsx_pci drm ptp pps_core wmi video fjes [ +0.000292] CPU: 2 PID: 11078 Comm: kworker/2:3 Tainted: G W 4.8.4-040804-generic #201610220733 [ +0.000092] Hardware name: Hewlett-Packard HP EliteBook Folio 9480m/22DA, BIOS M85 Ver. 01.34 01/18/2016 [ +0.000116] Workqueue: events drm_dp_destroy_connector_work [drm_kms_helper] [ +0.000075] task: ffff8e9ec6ac8e40 task.stack: ffff8e9ec687c000 [ +0.000055] RIP: 0010:[<ffffffff8d17fef7>] [<ffffffff8d17fef7>] device_del+0x17/0x260 [ +0.000086] RSP: 0018:ffff8e9ec687fd10 EFLAGS: 00010282 [ +0.000050] RAX: ffffffffc03fcaa0 RBX: fffffffffffffffe RCX: ffff8e9ef57e5810 [ +0.000072] RDX: 0000000080000000 RSI: ffff8e9ef57e7000 RDI: fffffffffffffffe [ +0.000064] RBP: ffff8e9ec687fd48 R08: ffff8e9f0fa98a00 R09: 0000000000000000 [ +0.000071] R10: 0000000000000000 R11: 000002f5cbbe1af3 R12: fffffffffffffffe [ +0.000066] R13: ffff8e9ef5504a90 R14: ffff8e9ef57e3010 R15: ffff8e9ef5504698 [ +0.000070] FS: 0000000000000000(0000) GS:ffff8e9f0fa80000(0000) knlGS:0000000000000000 [ +0.000082] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ +0.000055] CR2: fffffffffffffffe CR3: 000000043c9f8000 CR4: 00000000001406e0 [ +0.000086] Stack: [ +0.000035] ffff8e9ec687fd08 ffff8e9ec6ac8ec0 ffff8e9ef5aa7c90 fffffffffffffffe [ +0.000125] ffff8e9ef52b0000 ffff8e9ef5504a90 ffff8e9ef57e3010 ffff8e9ec687fd60 [ +0.000084] ffffffff8d18015a ffff8e9ef57e7000 ffff8e9ec687fd78 ffffffffc01c9314 [ +0.000096] Call Trace: [ +0.000035] [<ffffffff8d18015a>] device_unregister+0x1a/0x60 [ +0.000110] [<ffffffffc01c9314>] drm_sysfs_connector_remove+0x24/0x50 [drm] [ +0.000093] [<ffffffffc01cb1f7>] drm_connector_unregister.part.21+0x27/0x40 [drm] [ +0.000089] [<ffffffffc01cb224>] drm_connector_unregister+0x14/0x20 [drm] [ +0.000165] [<ffffffffc04172ea>] intel_dp_destroy_mst_connector+0x1a/0x80 [i915] [ +0.000087] [<ffffffffc02cb6c7>] drm_dp_destroy_connector_work+0xb7/0x160 [drm_kms_helper] [ +0.000085] [<ffffffff8cc9d43c>] process_one_work+0x1fc/0x4b0 [ +0.000060] [<ffffffff8cc9d73b>] worker_thread+0x4b/0x500 [ +0.000056] [<ffffffff8cc9d6f0>] ? process_one_work+0x4b0/0x4b0 [ +0.000062] [<ffffffff8cc9d6f0>] ? process_one_work+0x4b0/0x4b0 [ +0.000069] [<ffffffff8cca3a08>] kthread+0xd8/0xf0 [ +0.000056] [<ffffffff8d48311f>] ret_from_fork+0x1f/0x40 [ +0.000053] [<ffffffff8cca3930>] ? kthread_create_on_node+0x1b0/0x1b0
As a side note, I think the dock unit is fine, since my Windows 10 laptop (albeit a newer model) has no problems docking and undocking.