Re: [PATCH] support PCI MCFG space on Intel i915 bridges

[Robert Hancock <hancockr@shaw.ca>]

Jesse Barnes wrote:
> On Sunday, April 29, 2007 7:10 pm Robert Hancock wrote:
> > Jesse Barnes wrote:
> > > Add support for Intel 915 bridge chips to the new PCI MMConfig
> > > detection code.  Tested and works on my sole 915 based platform (a
> > > Toshiba laptop).  I added register masking per Oliver's suggestion,
> > > and moved the __init qualifier to after the 'static const char' to
> > > match Ogawa-san's recent cleanup patches.
> > >
> > > Signed-off-by:  Jesse Barnes <jesse.barnes@intel.com>
> > >
> > > diff --git a/arch/i386/pci/mmconfig-shared.c
> > > b/arch/i386/pci/mmconfig-shared.c index 747d8c6..1339d31 100644
> > > --- a/arch/i386/pci/mmconfig-shared.c
> > > +++ b/arch/i386/pci/mmconfig-shared.c
> > > @@ -72,6 +72,26 @@ static const char __init *pci_mmcfg_e7520(void)
> > >  	return "Intel Corporation E7520 Memory Controller Hub";
> > >  }
> > >
> > > +static const char __init *pci_mmcfg_intel_915(void)
> > > +{
> > > +       u32 pciexbar, len = 0;
> > > +
> > > +       pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0x48, 4, &pciexbar);
> > > +
> > > +       /* No enable bit or size field, so assume 256M range is
> > > enabled. */ +       len = 0x10000000U;
> > Check the 915 spec more carefully, there is an enable bit, it's in
> > the DEVEN register offset 54h, the bit is called PCIEXBAREN (bit 31).
> > If that is not set you should be setting pci_mmcfg_config_num to 0
> > and bailing out.
>
> Right, but you patch should obsolete this stuff anyway.  I'll test it 
> out in the next few days.

We likely still want this chipset-specific support, it will catch the 
case where the MCFG table lists a location which is reserved in ACPI but 
the chipset was actually programmed to a different location entirely, 
which I seem to remember someone mentioning was actually the case on 
some boards..

--
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/


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