I have a Dell Latitude E6440 equipped with Haswell processor and intel graphics, coupled with AMD hybrid graphics HD8690M.
I am currently using Debian testing/sid, where most hardware is recognized. Standard installation left me with the Intel graphics driver working. I have followed the installation instructions in the Debian Wiki for the proprietary AMD drivers. I can successfully login to my GNOME 3 session with discrete graphics enabled (via aticonfig --px-dgpu).
However, if I switch to integrated graphics mode (aticonfig --px-igpu), then neither GDM 3 nor (if using lightdm) GNOME 3 won't have it, granting me with the famous "Oh no something went wrong" screen and forcing me to drop to a tty.
I was wondering if any other people experienced this issue and whether they found a solution to it. In case not, I'd be willing to file a bug and help in triaging, but I am not sure which package is concerned, i.e. fglrx ? gdm ? gnome-shell ?