Re: [PATCH 2.6.18] PCI: Turn pci_fixup_video into generic for embedded VGA

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

On Thursday 28 September 2006 10:36, Jesse Barnes wrote:
> On Wednesday, September 27, 2006 9:55 pm, eiichiro.oiwa.nm@hitachi.com 
> wrote:
> > pci_fixup_video turns into generic code because there are many platforms
> > need this fixup for embedded VGA as well as x86. The Video BIOS
> > integrates into System BIOS on a machine has embedded VGA although
> > embedded VGA generally don't have PCI ROM. As a result, embedded VGA
> > need the way that the sysfs rom points to the Video BIOS of System RAM
> > (0xC0000). PCI-to-PCI Bridge Architecture specification describes the
> > condition whether or not PCI ROM forwards VGA compatible memory address.
> > fixup_video suits this specification. Although the Video ROM generally
> > implements in x86 code regardless of platform, some application such as
> > X Window System can run this code by dosemu86. Therefore,
> > pci_fixup_video should turn into generic code.
> ... 
> Thanks a lot, Eiichiro, this patch has been needed for awhile.

Are there really ia64 machines where we need to use the option ROM
copy at 0xC0000?  If so, is this documented somewhere?  I couldn't
find any mention in DIG64, EFI, or internal HP architecture specs.

If we do need to use it, ia64 has a bit of a problem because on some
boxes, the 0xC0000 memory supports only cacheable access, the VGA
frame buffer at 0xA0000 supports only uncacheable access, and the
usual ia64 ioremap mapping is a 16MB page that covers both.

Bjorn