Frequently Asked Questions

Installation

How do I know fglrx is installed correctly?

There are several ways to check if fglrx is loaded and running.
1. Check your X.org or XFree86 log. You should see "DRI Initialization Successful."

# vi /var/log/Xorg.0.log
or
# vi /var/log/XFree86.0.log

2. Check glxinfo. You should see "direct" and not "indirect."

# glxinfo | grep direct

3. Check your kernel log. You should see fglrx messages near the bottom.

# dmesg

4. Check your modules. You should see fglrx loaded.

# lsmod | grep fglrx

• NOTE: glxgears is not a definite way of checking the installation of fglrx.

Kernel

Why does fglrx not work for my bleeding-edge kernel?

The development process of the fglrx driver and the GNU/Linux kernel are not on the same level. The fglrx driver requires some special interactions with the kernel memory API and these tend to change between kernel versions.

ATI will only look to support the latest kernel that is officially out (no -rc or -git releases are supported) at the time they release a driver. Example: fglrx version A comes out Monday, but kernel version B comes out Tuesday. Kernel version B is not supported by fglrx version A. (but might be able to work anyway by doing a 'modprobe -f fglrx' in a shell)

The binary part of ATI's kernel module has no explicit dependency on the Linux kernel. There are a set of source files that provide the glue to the kernel. This is where the dependency to different kernels exist. As a result, user contributed patches for newer kernels can often be found by searching Bugzilla.

X Configuration

Composite Extension

If you've enabled transparency, and you've added the Composite extension to the xorg.conf file, the ATI driver will disable DRI.

The only way to use 3D and the ATI OpenGL drivers is commenting the Option "Composite" "Enable" line.

The composite extension is still considered "experimental" by the X.org organization and ATI has stated they will not support features that are classified as such.

Troubleshooting

Computer Freezes while using fglrx (UMA and SIDEPORT)

If after choosing fglrx as your driver in either xorg.conf or xfree86.conf files, the computer freezes and becomes unresponsive while trying to start X this may be the solution.

Some ATI cards have the ability to run in three modes: UMA, SIDEPORT, or a combination of both. UMA mode is that one in which the video card does not use its dedicated memory, but rather uses and shares the system memory. On the other hand, SIDEPORT mode is the one in which the card uses its own dedicated memory. And finally, the third mode is a combination of the previous modes in which the card uses both the system memory and its dedicated memory.

If your computer hangs, this settings may be where the solution lies. If your computer hangs, try using either UMA by itself or a combination of both. However, if you choose the combination, make sure that the UMA one is at least 128MB. In my case, I have SIDEPORT 128MB and 128MB UMA. If I choose any less for UMA, it does not work. This is definetly not an attractive solution since it compromises your systems performance. Hopefully, this will be solved very soon.

On some systems, the BIOS screen may not offer a choice of UMA or SIDEPORT. In this case, you can try turning the amount of RAM dedicated to the video card down, from 128Mb to 64Mb for example.