Comment 49 for bug 1290745

Pali (pali) wrote :

After upgrading kernel to 3.14 (plus adding radeon.runpm=0 to kernel cmdline) and upgrading xserver ati/radeon & intel drivers from git (version in trusty is not enough!), then *both* graphics cards (via dri prime) on Dell Latitude E6440 in Ubuntu Precise 12.04.4 started working.

$ glxinfo | grep OpenGL
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Haswell Mobile
OpenGL version string: 3.0 Mesa 10.2.0-devel
OpenGL shading language version string: 1.30
OpenGL extensions:

$ xrandr --setprovideroutputsource 1 0
$ DRI_PRIME=1 glxinfo | grep OpenGL
OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD HAINAN
OpenGL version string: 2.1 Mesa 10.2.0-devel
OpenGL shading language version string: 1.30
OpenGL extensions:

You can find kernel 3.14 (works with precise) on:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.14-trusty/

And xserver drivers in my PPA (for precise):
https://launchpad.net/~pali/+archive/graphics-drivers