1- Do update and upgrade as always.
apt-get update && apt-get upgrade && apt-get dist-upgrade -y
2- Install headers.
apt-get install linux-headers-`uname -r`
3-Install synaptic.
apt-get install synaptic -y
4-Open synaptic and type "bcm43142" and search.
5-U‘ll see 3 different drivers.
broadcom-sta-common
broadcom-sta-dkms
broadcom-sta-source
安装后依然没有解决....
6-Mark for installation to broadcom-sta-dkms and install it.
7-Reboot.
Read more at https://www.inforge.net/xi/threads/ls-cannot-access-sys-class-ieee80211-no-such-file-or-directory.454606/#jT8ThY4bq4BrwUHh.99
"ls: cannot access sys/class/ieee80211: No such file or directory" .
原文：http://www.cnblogs.com/blacksunny/p/6939990.html