Radeon HD4850 DRI Issues

[Robert Noland]

On Mon, 2009-12-07 at 15:50 -0500, Greg Rowe wrote:
> (II) RADEON(0): [pci] ring handle = 0xebe4f000
> (II) RADEON(0): [pci] Ring mapped at 0x28a50000
> (II) RADEON(0): [pci] Ring contents 0x55555555
> (II) RADEON(0): [pci] ring read ptr handle = 0xebf50000
> (II) RADEON(0): [pci] Ring read ptr mapped at 0x286ff000
> (II) RADEON(0): [pci] Ring read ptr contents 0x55555555

This is the root of the problem...  And I'm still baffled at how this
occurs...  It almost has to be either a BIOS issue or somehow a problem
with cache flushing.  What confuses me even further is that many i386
installs work fine, so it seems to point to the IOMMU possibly.  We
explicitly zero the ring space during allocation.

I'm cc'ing jhb@ in case he has any suggestions on what to look for...

robert.

-- 
Robert Noland <rnoland at FreeBSD.org>
FreeBSD