Re: [PATCH] And yet more PCI fixes for 2.5.70

From: Jeff Garzik (
Date: Wed Jun 11 2003 - 12:46:29 EST

On Wed, Jun 11, 2003 at 06:19:49PM +0100, Alan Cox wrote:
> On Mer, 2003-06-11 at 17:38, Greg KH wrote:
> > So that leaves only this file. Jeff Garzik and I talked about removing
> > pci_present() as it's not needed, and I think for this one case we can
> > live without it. Do you want me to make the pci_present() macro earlier
> > in this file, so it's readable again? I don't want to put it back into
> > pci.h.
> I still think it belongs in pci.h. Its an API and the API makes sense. The

Its an API that doesn't make sense.

99% of the uses can simply be eliminated (in 2.4, too).
They are entirely redundant.

The remaining two cases are really arch-specific checks that were
being done wrong anyway. Note the history: the definition morphed
in 2.4 from being "PCI BIOS seems to be present, so we'll assume a
PCI bus is present" to "PCI devices are present." Neither definition
is correct for the question the remaining two cases want answered:
"Is a PCI bus present?" Further, the IDE code calculating system
bus speed it should really be calling a PCI callback, not asking "Do
I have a PCI bus?" and making a guess... a guess which seems wrong
in several cases, including my Dual Athlon box w/ 100% 66 Mhz PCI bus.

So, I conclude that pci_present() is wrong for all cases except one --
and that case is sparc64-specific and can be handled with arch-specific
code, I bet.


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