Comment 46 for bug 1362848

I have Xubuntu 14.04 amd64 and this is how i fixed my black-screen problem. My hardware is Dell R15 N5110 with hybrid graphics Geforce M525 + Intel HD 3000. Left display is LVDS and right is HDMI.

Currently i have nvidia-355 and it works fine.

$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
01:00.0 VGA compatible controller: NVIDIA Corporation GF108M [GeForce GT 525M] (rev a1)

$ dpkg -l ubuntu-drivers-common
1:0.2.91.11

$ dpkg -l nvidia-common
1:0.2.91.11

$ prime-select query
nvidia

$ cat /etc/apt/sources.list.d/graphics-drivers-ppa-trusty.list
deb http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu trusty main
# deb-src http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu trusty main

$ cat /etc/lightdm/display_fix.sh
#/bin/bash
xrandr --setprovideroutputsource Intel NVIDIA-0
xrandr --auto
xrandr --output LVDS1 --left-of HDMI-0
xrandr --output LVDS1 --primary
exit

$ cat /etc/lightdm/lightdm.conf.d/20-custom.conf
[SeatDefaults]
display-setup-script=/etc/lightdm/display_fix.sh

$ cat /etc/X11/xorg.conf
Section "ServerLayout"
    Identifier "layout"
    Screen 0 "nvidia"
    Inactive "intel"
EndSection

Section "Device"
    Identifier "intel"
    Driver "intel"
    BusID "PCI:0@0:2:0"
    Option "AccelMethod" "SNA"
EndSection

Section "Screen"
    Identifier "intel"
    Device "intel"
EndSection

Section "Device"
    Identifier "nvidia"
    Driver "nvidia"
    BusID "PCI:1@0:0:0"
    Option "ConstrainCursor" "off"
EndSection

Section "Screen"
    Identifier "nvidia"
    Device "nvidia"
    Option "AllowEmptyInitialConfiguration" "on"
    Option "IgnoreDisplayDevices" "CRT"
EndSection

$ chmod +x /etc/lightdm/display_fix.sh
$ chattr +i /etc/X11/xorg.conf