I have the same graphical chipset in my MSI S420 laptop, and I encounter the same. I found that adding
Option "GARTSize" "128"
in my Device section of /etc/X11/xorg.conf does make it work. However, DRI does not initialize correctly. From /var/log/Xorg.0.log
(II) RADEON(0): [dri] Found DRI library version 1.3.0 and kernel module version 1.27.0
(EE) RADEON(0): [pci] PCI failed to initialize. Disabling the DRI. ... (EE) AIGLX: Screen 0 is not DRI capable
I have the same graphical chipset in my MSI S420 laptop, and I encounter the same. I found that adding
Option "GARTSize" "128"
in my Device section of /etc/X11/xorg.conf does make it work. However, DRI does not initialize correctly. From /var/log/Xorg.0.log
(II) RADEON(0): [dri] Found DRI library version 1.3.0 and kernel module version 1.27.0
(EE) RADEON(0): [pci] PCI failed to initialize. Disabling the DRI.
...
(EE) AIGLX: Screen 0 is not DRI capable