Issue with Xorg memory leak with Radeon fglrx proprietary drivers
I decided to try the open source drivers for my Radeon HD 7770,
because I had an issue with Xorg memory leak that seems related
with the AMD Catalyst proprietary drivers.
You can read about the memory leak bug in the following links:
So, in case this helps someone, here are the steps in Debian 8 to revert to the open source drivers and configure dual monitors:
Reverting to the open source drivers
First, if you have installed the proprietary drivers fglrx, you can revert to the open source drivers as follows:
Revert to open source graphics drivers
Radeon HD 7700 with open source radeon drivers, install the correct firmware in Debian 8
Debian Wiki AtiHowTo says to install firmware-linux-nonfree, but that did not work well for me.
instead of firmware-linux-nonfree I installed firmware-amd-graphics
firmware-amd-graphics is not compatible with firmware-linux-nonfree, so apt-get will uninstall firmware-linux-nonfree
before installing firmware-amd-graphics
reboot and then
dmesg should display the firmware/microcode used by the radeon DRM driver:
and the output of xrandr should display the 2 monitors:
Configuring the Dual monitors
Depending on your desktop environment, it is possible that X still displays the same content mirrored in both monitors (instead of expanding the desktop)
Desktops like gnome and kde have their own tools to configure the dual monitors desktop.
If you are using a minimal desktop like awesome window manager , and you need a simple application to configure the dual monitors, you can try arandr that is a gui interface to xrandr.
arandr will allow you to use a gui to select the position of the monitors, and it will generate a bash script invoking xrandr with the correct parameters that we can use anytime.
Here is a sample bash script that is produced by arandr to configure the dual monitors on my PC: