Followup on #39 - I have just noticed that the backlight switches on after few seconds of inactivity (14.04.4 with 4.2 kernel). AFAIK this wasn't the case with 4.4 kernel (16.04).
I also checked and after opening the laptop lid and waking up, the backlight is off, just as in 4.4 (at least on my model, Dell Latitude E6420).
Followup on #39 - I have just noticed that the backlight switches on after few seconds of inactivity (14.04.4 with 4.2 kernel). AFAIK this wasn't the case with 4.4 kernel (16.04).
I also checked and after opening the laptop lid and waking up, the backlight is off, just as in 4.4 (at least on my model, Dell Latitude E6420).