I used to switch graphics card from integrated (Intel GMA4500) to discrete (Radeon 4500 HD) using the command:
echo DDIS > /sys/kernel/debug/vgaswitcheroo/switch
followed by a logout.
This kept the login manager visible on the laptop, allowing to log back in etc etc.
Now, when I logout the LVDS-1 output becomes black and the only way to have the screen visible is to plug an external monitor to the HDMI port of the discrete radeon4500HD card which is HDMI-0 port.
if I login, then the responsiveness of the interface on the laptop screen is extremely slow, whereas it is fast on the external monitor.
I can make it quick also on the laptop display by selecting “Same output on all monitors” from the display settings (Mate desktop).
However, as I unplug the HDMI cable, the interface and responsiveness on the laptop screen goes back to extremely slow.
I would like to have the discrete graphics card to output properly to the laptop screen as it used to before.
Can anybody help please?
touchsmart tm2 1090 eg Laptop
GPU: Intel GMA4500 + Radeon mobility HD4500
RV710/M92 [Mobility Radeon HD 4350/4550] (ATI Technologies Inc)
Mobile 4 Series Chipset Integrated Graphics Controller (Intel Corporation)
Display manager: lightdm