Comment 7 for bug 1647036

I have also tested the backported kernel in Xenial, and the module builds and works well (as with 4.4).

uname -r

4.8.0-35-generic

modinfo wl

filename: /lib/modules/4.8.0-35-generic/updates/dkms/wl.ko
license: MIXED/Proprietary
srcversion: 0ADAE750C888A523D63D8B5
alias: pci:v*d*sv*sd*bc02sc80i*
depends: cfg80211
vermagic: 4.8.0-35-generic SMP mod_unload modversions
parm: passivemode:int
parm: wl_txq_thresh:int
parm: oneonly:int
parm: piomode:int
parm: instance_base:int
parm: nompc:int
parm: intf_name:string

apt-cache policy linux-generic-hwe-16.04

linux-generic-hwe-16.04:
  Installed: 4.8.0.35.7
  Candidate: 4.8.0.35.7
  Version table:
 *** 4.8.0.35.7 400
        400 http://it.archive.ubuntu.com/ubuntu xenial-proposed/main amd64 Packages
        100 /var/lib/dpkg/status