WiFi not working after latest Ubuntu software update

Question

I have a Dell laptop running Ubuntu 14.04 LTS I purchased it new about a month ago. This morning I got a popup about a Software Update available, so I updated, and now the wifi is not working at all. I checked the networking menu and it shows NO networks detected. Everything worked just fine until this latest software update.

Here's the output from lspci -knn | grep Net -A2

3a:00.0 Network Contoller [0280]: Intel Corporation Wireless 8260 [8086:24f3] (rev 3a)
         Subsystem: Intel Corporation Device [8086:0050]
3b:00.0 Unassingned class [ff00]: Realtek Semiconductor Co. ltd. Device [10ec:525a] (rev 01)

I tried the mokutil disable validation as described in the other problem report

sudo apt install mokutil sudo mokutil --disable-validation

it forced me to create a new password, but still no wifi!!!

Here is lspci -vvnn 3a.00.0 Network Controller [0280]: Intel Corporation Wireless 8260 [8086:24f3] (rev 3a) Subsytem : Intel Corporation Device [8086:0050] Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B- ParERR- DEVSEL=fast >TAbort- SERR-

What driver should I have for the Intel 8260? I did lmod and I didn't see anything that looked like a wifi driver...

Possible duplicate of Why do I get "Required key not available" when install DKMS modules? — Pilot6, Jul 23 '16 at 20:41
I did not get any error about "Required key not available" and have NEVER installed any "DKMS modules", is this still the same issue? — MattB, Jul 23 '16 at 20:42
Let's see what you installed ot not. Please [edit] your question and add output of lspci -knn | grep Net -A2 terminal command. — Pilot6, Jul 23 '16 at 20:45
@http://askubuntu.com/users/571701/mattb: You don't "add newlines to a comment"! You "Edit" the original post and add the information, with formatting. — waltinator, Jul 24 '16 at 00:15
How do I tell if a software update includes a kernel upgrade? — MattB, Jul 24 '16 at 00:22

score 2 · Answer 1 · answered Jul 26 '16 at 08:16

2

I booted in to the Bios Menu page, but hitting F-12 when the Dell logo appeared during boot up... I found the SecureBootMode setting under the Security settings, and disabled it, then after rebooting everything was fine.

answered Jul 26 '16 at 08:16

MattB

191

score 0 · Answer 2 · answered Jul 26 '16 at 08:21

0

It looks like you installed a custom dkms driver to support your 8260 adapter. You can check it by

dkms status

terminal command.

Secure Boot does not allow to load 3rd party unsigned kernel modules.

Now Intel 8260 adapters are supported by new Ubuntu kernels.

The best solution will be to remove that dkms module and upgrade the kernel to 4.4 by running

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

This way the wireless adapter will work with Secure Boot on and you will not depend on kernel compatibility with a custom module.

answered Jul 26 '16 at 08:21

Pilot6

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NO, I didn't install any custom dkms driver, unless it came with the most recent sofware update... Or it was pre-installed on this computer as part of this Dell/Ubuntu load.. – MattB Jul 26 '16 at 18:00
I edited the BIOS to disable Secure Boot and it seems to be fine now. – MattB Jul 26 '16 at 18:00
What should I look for in dkms status? – MattB Jul 26 '16 at 18:02

WiFi not working after latest Ubuntu software update

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