I have to run Ubuntu 14.04 on a MacBook Air 2014. After installing the OS years ago, I remember having to install a wifi driver manually using an ethernet connection. Wifi has worked flawlessly ever since, until today.

After being prompted by System Updater to do a routine kernel update and restart afterwards, my wifi suddenly stopped working.

When I type "wifi on" on the command line, I now get:

wifi      = none (no device)

And the command "sudo modprobe wl" now gives me:

modprobe: FATAL: Module wl not found.

After reading other threads, I tried reinstalling the bcmwl-kernel-source package, to no avail.

For reference, the relevant portion of the output of sudo lspci -v is:

03:00.0 Network controller: Broadcom Corporation BCM4360 802.11ac Wireless Network Adapter (rev 03)

    Subsystem: Apple Inc. Device 0117

    Flags: bus master, fast devsel, latency 0

    Memory at b0600000 (64-bit, non-prefetchable) [size=32K]

    Memory at b0400000 (64-bit, non-prefetchable) [size=2M]

    Capabilities: [48] Power Management version 3

    Capabilities: [58] MSI: Enable- Count=1/1 Maskable- 64bit+

    Capabilities: [68] Vendor Specific Information: Len=44 <?>

    Capabilities: [ac] Express Endpoint, MSI 00

    Capabilities: [100] Advanced Error Reporting

    Capabilities: [13c] Device Serial Number 8c-29-00-ff-ff-00-00-01

    Capabilities: [150] Power Budgeting <?>

    Capabilities: [160] Virtual Channel

    Capabilities: [1b0] Latency Tolerance Reporting

    Capabilities: [220] #15

Thank you for your help

Edit:

"sudo dpkg -s bcmwl-kernel-source" gives:

Package: bcmwl-kernel-source

Status: install ok installed

Priority: optional

Section: admin

Installed-Size: 7902

Maintainer: Ubuntu Developers <[email protected]>

Architecture: amd64

Source: bcmwl

Version: 6.30.223.271+bdcom-0ubuntu1~0.1

Replaces: bcmwl-modaliases

Depends: dkms, linux-libc-dev, libc6-dev

Conflicts: bcmwl-modaliases

Description: Broadcom 802.11 Linux STA wireless driver source

 This package contains Broadcom 802.11 Linux STA wireless driver

 for use with Broadcom's BCM4311-, BCM4312-, BCM4313-, BCM4321-,

 BCM4322-, BCM43224-, and BCM43225-, BCM43227- and BCM43228-based

 hardware.

Modaliases: wl(pci:v000014E4d00004311sv*sd*bc02sc80i*, pci:v000014E4d00004312sv*sd*bc02sc80i*, pci:v000014E4d00004313sv*sd*bc02sc80i*, pci:v000014E4d00004315sv*sd*bc02sc80i*, pci:v000014E4d00004727sv*sd*bc02sc80i*, pci:v000014E4d00004328sv*sd*bc02sc80i*, pci:v000014E4d00004328sv*sd*bc02sc80i*, pci:v000014E4d00004329sv*sd*bc02sc80i*, pci:v000014E4d0000432asv*sd*bc02sc80i*, pci:v000014E4d0000432bsv*sd*bc02sc80i*, pci:v000014E4d0000432csv*sd*bc02sc80i*, pci:v000014E4d0000432dsv*sd*bc02sc80i*, pci:v000014E4d00004365sv*sd*bc02sc80i*, pci:v000014E4d00004353sv*sd*bc02sc80i*, pci:v000014E4d00004357sv*sd*bc02sc80i*, pci:v000014E4d00004358sv*sd*bc02sc80i*, pci:v000014E4d00004359sv*sd*bc02sc80i*, pci:v000014E4d00004331sv*sd*bc02sc80i*, pci:v000014E4d000043a0sv*sd*bc02sc80i*, pci:v000014E4d000043B1sv*sd*bc02sc80i*)

Original-Maintainer: Alberto Milone <[email protected]>

"sudo updatedb && locate wl.ko" gives no output.

Second edit:

sebastien:~$ sudo apt-get install --reinstall bcmwl-kernel-source

[sudo] password for sebastien: 

Reading package lists... Done

Building dependency tree       

Reading state information... Done

0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 4 not upgraded.

Need to get 1,545 kB of archives.

After this operation, 0 B of additional disk space will be used.

WARNING: The following packages cannot be authenticated!

  bcmwl-kernel-source

Install these packages without verification? [y/N] y

Get:1 http://us.archive.ubuntu.com/ubuntu/ trusty-proposed/restricted bcmwl-kernel-source amd64 6.30.223.271+bdcom-0ubuntu1~0.1 [1,545 kB]

Fetched 1,545 kB in 1s (1,010 kB/s)              

(Reading database ... 297568 files and directories currently installed.)

Preparing to unpack .../bcmwl-kernel-source_6.30.223.271+bdcom-0ubuntu1~0.1_amd64.deb ...

Removing all DKMS Modules

Done.

Unpacking bcmwl-kernel-source (6.30.223.271+bdcom-0ubuntu1~0.1) over (6.30.223.271+bdcom-0ubuntu1~0.1) ...

Setting up bcmwl-kernel-source (6.30.223.271+bdcom-0ubuntu1~0.1) ...

Loading new bcmwl-6.30.223.271+bdcom DKMS files...

Building only for 3.13.0-164-generic

Building for architecture x86_64

Module build for the currently running kernel was skipped since the

kernel source for this kernel does not seem to be installed.

modprobe: FATAL: Module wl not found.

update-initramfs: deferring update (trigger activated)

Processing triggers for shim-signed (1.33.1~14.04.3+13-0ubuntu2) ...

Secure Boot not enabled on this system.

Processing triggers for initramfs-tools (0.103ubuntu4.11) ...

update-initramfs: Generating /boot/initrd.img-3.13.0-164-generic