wake from suspend fails when using discrete videocard on hybrid system

[Egor]

My laptop (ASUS K501UW-AB78) fails to resume from suspend when using Nvidia driver and Nvidia videocard is active. The problem does not arise when I switch to built-in video using nvidia prime or when using nouveau driver.

Since this appears to only be relevant for hybrid systems, I file the bug under nvidia-prime; please move as appropriate.

what I expect to happen: when system is in suspend and I open laptop lid or press any button, the laptop resumes and brings up the lock screen.

what actually happens: when system is in suspend and I open laptop lid or press any button, the laptop awakens (power and wifi LEDs turn on); the screen gets backlit but remains black. I cannot switch to terminal session via Ctrl+Alt+F1. I am unable do anything blindly (for example, type in the password and try to turn off the laptop via keyboard combinations).

to replicate the problem: install ubuntu 16.04, install nvidia driver via "additional drivers" settings dialog. Open nvidia-settings, open PRIME tab, switch to NVIDIA (performance mode), log out, log in, suspend the pc, press any button.

Tested on: Ubuntu Mate 16.04.1 LTS x64 and Linux Mint 18 Cinnamon x64; in both cases kernel 4.4.
Driver version: 361.42, nvidia-prime v0.82. I tried to manually install 367.44 driver, but both systems failed to load with that one (unlike my desktop).
Hardware: Nvidia GTX 960M and Intel HD 520 (in intel i7 6500u cpu) videocards.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: nvidia-prime 0.8.2
ProcVersionSignature: Ubuntu 4.4.0-31.50-generic 4.4.13
Uname: Linux 4.4.0-31-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: MATE
Date: Sun Sep 4 21:52:32 2016
InstallationDate: Installed on 2016-09-05 (0 days ago)
InstallationMedia: Ubuntu-MATE 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: nvidia-prime
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.