First, I've read and tried the question here (Display issue on Toshiba Satellite P75-A7200) There an issue at boot is described. For me, my display shows up after boot but them I'm having other issues (lags, etc.) See UPDATE.
I'm using the integrated graphics in Intel's i7 4700QM processor, so Intel's HD graphics 4600. I've been looking into the issue and found this.
- System testing fails the graphics test (compiz not supported, no driver, etc.)
- Output from
lshwsays my *-display, *-serial and *-power are UNCLAIMED
- Installing Intel's Linux Graphics Drivers (https://01.org/linuxgraphics/downloads/2013/intelr-linux-graphics-installer-version-1.0.2) does nothing to fix this.
How can I "claim" the display? (Ideally I could also "claim" serial and power, but the display is more pressing for me).
The solution in Display issue on Toshiba Satellite P75-A7200 DOES work BUT you need to get rid of the nomodeset option (which I used initially to install ubuntu in the first place). The nomodeset option causes the video drivers not to load at all (even though I think the description says that they load later). I reinstalled ubuntu with the options on that link and then updated
/etc/default/grub as instructed there. Now *-display is not showing unclaimed.
My fn keys don't all work (I created a custom shortcut for at least the brightness using
xdotool) and there's other minor things, but overall the computer seems to be working fine now.