Re: [patch] Make MMCONFIG space (extended PCI config space) a driver opt-in issue

Arjan van de Ven
2007-12-22T14:48:30Z

On Sat, 22 Dec 2007 09:20:06 -0500
Jeff Garzik <jeff@garzik.org> wrote:

> Arjan van de Ven wrote:
> > Hi,
> >
> > Linus really wants the extended (4Kb) PCI configuration space
> > (using MCFG acpi table etc) to be opt-in, since there's many issues
> > with it and most drivers don't even use/need it. The idea behind
> > opt-in is that if you don't use it, you don't get to suffer the
> > bugs...
> >
> > Booted on my 64 bit test machine; sadly it has a defunct BIOS that
> > doesn't have a working MCFG.
> >
> >
> > From: Arjan van de Ven <arjan@linux.intel.com>
> > Subject: Make MMCONFIG space a driver opt-in
> >
> > There are many issues with using the extended PCI configuration
> > space (CPU, Chipset and most of all BIOS bugs). This while the vast
> > majority of drivers and devices don't even use/need to use the
> > memory mapped access methods since they don't use the config space
> > beyond the traditional 256 bytes.
> >
> > This patch makes accessing the extended config space a driver
> > choice, via the
> >
> > pci_enable_ext_config(pdev)
>
> Yuck. And, Linus is just being silly. Wait a year then turn on
> MMCONFIG :) It took PCI MSI a while to mature, but is finally
> getting there.
>

Do you hate the name or the concept? I'm certainly open for a better name....