I have an ASUS ux303ln with Xubuntu 15.04 that hosts Nvidia 840M. Aiming for longer battery life, I want to use the Intel graphics, so i do
prime-select intel
as root and that's OK.
The problem is when the laptop resumes from sleep - if I am with the Intel driver, the screen is not repainted - it is grey or just the last desktop image - I cannot regain my session and have to restart lightdm or the computer. Tested with Nvidia drivers 340.76, 346.59, 352.21 and noveau.
Anyone has an idea what could cause this?