Q:

How do I get an Intel Wireless 3168 802.11ac wireless card to work? 

I have recently bought HP Pavilion 15 AU113TX laptop, which comes with Intel Core i5 7200U Kaby Lake processor, I have installed Ubuntu GNOME 16.04.1 on it, and it is unable to detect WiFi adapter. 

Upon running lspci -nnk | grep -A2, I'm getting following information about adapter. 
028005:00.0 Network controller [0280]: Intel Corporation Device [8086:24fb] (rev 10)
        DeviceName: Intel Dual BandWireless-AC 3168 802.11 ac 1x1 WiFi + BT 4.0 Combo Adapter
        Subsystem: Intel Corporation Device [8086:2110]

But running rfkill list all, I see following output (WiFi missing there). 
0: hci0: Bluetooth
        Soft blocked: no
        Hard blocked: no

And here's the output for dmesg | grep iwl. 
[   13.570633] iwlwifi 0000:05:00.0: Unsupported splx structure
[   13.635662] iwlwifi 0000:05:00.0: Direct firmware load for iwlwifi-3168-21.ucode failed with error -2
[   13.650761] iwlwifi 0000:05:00.0: Direct firmware load for iwlwifi-3168-20.ucode failed with error -2
[   13.650765] iwlwifi 0000:05:00.0: no suitable firmware found! 

Output for ls -al /lib/firmware | grep 3168 Under both Stock Kernel 4.4.0-36 & Kernel 4.7.3. 
-rw-r--r--  1 root root   33168 Jul 13 01:03 hfi1_pcie.fw

Please note that this laptop is dual booted with Windows 10 Home, and WiFi is working fine there. 
Now, I don't know if this adapter is supported by 4.4 kernel that Ubuntu 16.04 ships with, or it requires manual fix, as my laptop doesn't have hardware switch to turn on/off WiFi.  Also, this being a combo adapter for both WiFi and Bluetooth, I can use Bluetooth just fine.  Ethernet works too. 
After searching around Intel® Dual Band Wireless-AC 3168 I found this page which suggests that support for this Wireless Adapter was added starting Kernel v4.6, and since 16.04 has Kernel 4.4, I tried two things. 
1) Upgrade Kernel
I manually installed 4.7.3 from kernel.ubuntu.com, and booted into it but WiFi still remains undetected. 
2) Loading firmware for this adapter version (3168). 
I searched for .ucode files for this adapter and found it on OpenELEC's GitHub.  So I copied iwlwifi-3168-21.ucode and iwlwifi-3168-22.ucode files to /lib/firmware/ and rebooted, but still no luck. 

Update
This seems to be a linux-firmware related bug, and I have filed the report on Launchpad.  However, workaround given by Jeremy31 seems to fix WiFi under Kernel 4.7.4, but it breaks Bluetooth which was working fine with Stock Kernel 4.4.0-38.  I'm still looking for a proper fix which doesn't cause any regressions (I'm fine with upgrading to newer stable Kernel release). 

A:

You have an issue with firmware for the device with the 4.7 kernel
wget http://mirrors.kernel.org/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.161_all.deb
sudo dpkg -i linux-firmware_1.161_all.deb
Reboot into the 4.7 kernel and your wireless should function

A:

I have the exact same laptop and had this very issue and I'm so glad I found this thread.  As @Jeremy31 suggested, it is a bug with the linux-firmware. 
I did a sudo apt dist-upgrade and upgraded to the 4.8.*  kernel and just everything works
Relevant info : 
uname -a 

Linux pwnbox 4.8.0-17-generic #19-Ubuntu SMP Sun Sep 25 05:29:05 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

Bluetooth : 

Wi-Fi : 

A:

I have the same issue but on different laptop.  This laptop is an Acer Extensa 2540.  I did a clean install of Ubuntu 16.04.2 and later run this single command:
apt install linux-generic-hwe-16.04

You can find more information about HWE here
https://wiki.ubuntu.com/Kernel/LTSEnablementStack

