Subject: Re: xf 4.0.1 with rage II/rage pro -- multi-headed display!

From: Benjamin Herrenschmidt <[email-masked]>
Date: Wed, 27 Sep 2000 19:22:30 +0200

>> One thing: I'd be interested in figuring out what happens if you simply
>> leave this nasty ATI BAR unassigned (write 0xffffffff and then 0 to it).
>> Will the controller fail ?
>
>Well, according to Matt Porter, 0 is a valid address in PCI 2.2. So how
do you
>disable BARs for PCI 2.2-compliant devices?
>
>And I'm afraid what XFree86 4.x will do with BARs set to 0. Probably it will
>try to relocate them. I guess that's how it crashes on my box with an
>unitialized S3...

Well, I may be wrong here, but the cause of our problem (the MMIO BAR
overlapping the framebuffer BAR causing XFree to bark) may also be an
XFree problem. I think we never completely figured out if what MacOS does
to the chip is valid or not (because of priority-decoding).

Ben.

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