LinuxQuestions.org - XFree86 and Write-Combining Range ?

Hey all,

I just recompiled a shiny new 2.6.0-test2 kernel successfully last night after getting/installing modutils and the like needed for the new module implementation.

Seems to be working great, I've got framebuffer on boot, soundcard working with OSS drivers (alsa produced different crackling effects over sound every time the modules were loaded), usb Mouse, onboard ethernet, and just about everything working.

But now, I can't compile drivers for my Radeon 9000 Pro, and I'm getting this message with both the XFree "radeon" driver and the "vesa" driver. I can still load X, but it's painfully slow.

This is the error that I believe is causing the problem-

Snippet from XFree86.0.log

Code:

(II) VESA(0): Primary V_BIOS segment is: 0xc000

(II) VESA(0): VESA BIOS detected

(II) VESA(0): VESA VBE Version 2.0

(II) VESA(0): VESA VBE Total Mem: 65536 kB

(II) VESA(0): VESA VBE OEM: ATI RADEON RV250

(II) VESA(0): VESA VBE OEM Software Rev: 1.0

(II) VESA(0): VESA VBE OEM Vendor: ATI Technologies Inc.

(II) VESA(0): VESA VBE OEM Product: V250

(II) VESA(0): VESA VBE OEM Product Rev: 01.00

(WW) VESA(0): Failed to set up write-combining range (0xd8000000,0x4000000)

(II) VESA(0): virtual address = 0x40281000,

        physical address = 0xd8000000, size = 67108864

(II) VESA(0): VBESetVBEMode failed...Tried again without customized values.

(==) VESA(0): Default visual is TrueColor

(==) VESA(0): Backing store disabled

(**) Option "dpms" "true"

(**) VESA(0): DPMS enabled

I did some reading and found that enabling MTRR in the kernel is supposed to enable Write Combining for display drivers... But it IS compiled into my new kernel.

What's going on here?

Thanks in advance for any ideas:)
-Shade