Hi I managed to install the ati-radeon driver on my realtime-kernel driven system. ( Debian GNU/Linux, 2.6.31-rt11 ) For your information, here is how I did. I downloaded the linux driver from: http://support.amd.com/us/gpudownload/Pages/index.aspx This information applys to "ATI Radeon HD 3xxx Series" only, but other drivers might require likewise changes. Installer used: ati-driver-installer-9-10-x86.x86_64.run --------- 1. Start the installer. But don't continue. This will extract the installer-files to the current directory. 2. Open a new terminal, change to the extracted directory (called something as fglrx-install.08df92 ). 3. CHANGE THE FILE: firegl_public.c in install/lib/modules/fglrx/build_mod/firegl_public.c (and maybe: common/lib/modules/fglrx/build_mod/firegl_public.c ) AS FOLLOWS: THIS (LINE ~ 1028): for (i = 0; i < __KE_MAX_SPINLOCKS; i++) dev->spinlock[i] = SPIN_LOCK_UNLOCKED; CHANGES TO: for (i = 0; i < __KE_MAX_SPINLOCKS; i++) DEFINE_SPINLOCK( dev->spinlock[i] ); THIS (LINE ~ 5001): init_MUTEX(&(mutex_obj->mutex)); CHANGES TO: semaphore_init( &(mutex_obj->mutex) ); 4. go back to the installation terminal, continue and finish the installation. good luck. -- E.R.