Comment 95 for bug 1510344

I found another solution, seems to be better because, kernel version 4.4.0.21 has a bug within the suspend mode(sometimes works and sometimes not) at least, happened to me in a Dell latitude e6420 and also this bug of the backlight, so to fix it I updated the kernel version to 4.7.5 -- The only problem was that wireless stopped working, so to fix it I connected through wired connection and I changed the driver, after that all works well!

check this: http://askubuntu.com/questions/574920/upgrading-to-3-18-kernel-causes-wireless-not-to-work

**may be help:)
Sorry for my bad english.