My laptop Lenovo z50-70 with Ubuntu 14.04 has wifi issue.
Wifi gets connected after restarting the laptop. But after sometimes it stops functioning though the wifi icon shows proper connected status. After getting disconnected, it never reconnects before I restart the laptop.
uname -a
Linux Lenovo-Z50-70 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux