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    SubjectRe: VGA PCI IO port reservations
    Russell King wrote:
    > Jeff Garzik writes:
    > > If XFree86 not fbdev is using the hardware, you can always have a stub
    > > driver that does nothing but reserve the ports. Remember, too, that the
    > > ports claimed depend on register settings in the video card and PCI
    > > config space..
    > I wish. Unfortunately, ones of this nature tend to be rather fixed. No amount
    > of config space twiddling will move them. However, as someone else pointed out,
    > x86 gets around this problem by only allowing IO ports to be allocated in the
    > (addr & 0x0300) == 0 range, thereby avoiding the problem.

    Dig through the video card docs, even older ISA video cards let you
    disable I/O decoding on all but a few ports, and/or relocate the ports
    it does use to other areas. Different with every video card, of course,
    but most of them can do this to a greater or lesser extent.


    Jeff Garzik |
    Building 1024 | The chief enemy of creativity is "good" sense
    MandrakeSoft | -- Picasso
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