No wireless networks detected in 14.04 after reboot

Question

I have a new Dell XPS 13 developer edition with 14.04. There have been no issues for the first few weeks, but after rebooting my computer yesterday I no longer detect wireless networks. How can I get it to work again?

Here are a few things I've done after googling this problem.

lshw -C network gives:

 *-network UNCLAIMED     
      description: Network controller
      product: Wireless 8260
      vendor: Intel Corporation
      physical id: 0
      bus info: pci@0000:3a:00.0
      version: 3a
      width: 64 bits
      clock: 33MHz
      capabilities: pm msi pciexpress cap_list
      configuration: latency=0
      resources: memory:dc200000-dc201fff

iwconfig gives

    lo        no wireless extensions.
    eth0      no wireless extensions.

nm-tool clearly detect the wired connection but doesn't mention anything about wireless connections.

I've run the wireless info script in the answer to this question. The output is here.

What happened? Why did it suddenly stop working and why is it not working now? What does it mean that the network is "unclaimed"?

EDIT: Output from dkms status as requested:

~$ dkms status
btusb-iwlwifi-intel8260, 1.7, 3.19.0-33-generic, x86_64: installed
btusb-iwlwifi-intel8260, 1.7, 3.19.0-65-generic, x86_64: installed
intel-hid, 2.0, 3.19.0-33-generic, x86_64: installed
intel-hid, 2.0, 3.19.0-65-generic, x86_64: installed
oem-audio-hda-daily-lts-vivid, 0.201512022217~ubuntu14.04.1, 3.19.0-33-generic, x86_64: installed
oem-audio-hda-daily-lts-vivid, 0.201512022217~ubuntu14.04.1, 3.19.0-65-generic, x86_64: installed
realtek-rts-cr, 1.4.3oem2, 3.19.0-33-generic, x86_64: installed
realtek-rts-cr, 1.4.3oem2, 3.19.0-65-generic, x86_64: installed
synaptic-i2c-hid-3.13.0-32-backport, 1.6.4: added

Please [edit] your question and add output of dkms status terminal command. — Pilot6, Aug 06 '16 at 21:38
@Pilot6 I actually already solved my own problem. Do you know why disabling secure boot fixed it? — Mark Girard, Aug 06 '16 at 21:43
It looks like you installed lots of custom modules. They do not work any more. I suggest removing them all. — Pilot6, Aug 06 '16 at 22:04

score 0 · Answer 1 · answered Aug 06 '16 at 21:36

0

I have no idea why this worked, but rebooting and disabling secure boot completely solved my problem. I found the solution somewhere else.

Can someone explain to me why disabling secure boot fixed this for me?

answered Aug 06 '16 at 21:36

Mark Girard

113

You installed a custom kernel module that does not work with Secure Boot any more. – Pilot6 Aug 06 '16 at 21:39

score 0 · Answer 2 · edited Apr 13 '17 at 12:25

You installed a custom kernel DKMS module btusb-iwlwifi-intel8260.

The latest Ubuntu kernels do not load 3rd party kernel modules that are not signed if Secure Boot is enabled. You can see this question for more details.

Kernel 3.19 should support this adapter now without any custom module, but I am not 100% sure, because I did not test it.

I am quite sure that the 4.4 kernel does support this adapter out of the box. This kernel is available from the official repositories for Ubuntu 14.04.

You can remove the btusb-iwlwifi-intel8260 by this command:

sudo dkms remove btusb-iwlwifi-intel8260/1.7 --all

and see if Wi-Fi work after reboot.

If it does, you can enable Secure Boot and it will keep working with the updated in-tree module.

If it does not, you can always upgrade the kernel by

sudo apt-get install linux-generic-lts-xenial

With this kernel Intel 8260 will work with Secure Boot on for sure.

No wireless networks detected in 14.04 after reboot

2 Answers2