Comment 8 for bug 565790

I noticed the following entries in the boot dmesg messages:

[ 17.846987] [drm] radeon defaulting to kernel modesetting.
[ 17.846990] [drm] radeon kernel modesetting enabled.
[ 17.847037] radeon 0000:01:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16
[ 17.847042] radeon 0000:01:00.0: setting latency timer to 64
[ 17.849248] [drm] radeon: Initializing kernel modesetting.
[ 17.863917] [drm] register mmio base: 0xDFDF0000
[ 17.863920] [drm] register mmio size: 65536
[ 17.863978] ATOM BIOS: 113
[ 17.863993] [drm] Clocks initialized !
[ 17.864016] mtrr: type mismatch for c0000000,10000000 old: write-back new: write-combining
[ 17.864019] [drm] Detected VRAM RAM=256M, BAR=256M
[ 17.864020] [drm] RAM width 64bits DDR
[ 17.869406] [TTM] Zone kernel: Available graphics memory: 1996288 kiB.
[ 17.869422] [drm] radeon: 256M of VRAM memory ready
[ 17.869424] [drm] radeon: 512M of GTT memory ready.
[ 17.869462] alloc irq_desc for 29 on node -1
[ 17.869464] alloc kstat_irqs on node -1
[ 17.869473] radeon 0000:01:00.0: irq 29 for MSI/MSI-X
[ 17.869478] [drm] radeon: using MSI.
[ 17.869506] [drm] radeon: irq initialized.

Perhaps booting with radeon.modeset=0 fixes this; or booting with pci=nomsi ( https://bugs.launchpad.net/ubuntu/+source/linux/+bug/509273 )