[coreboot] PCI MMCONF on amdfam10

[Stefan Reinauer]

* Kyösti Mälkki <kyosti.malkki at gmail.com> [131212 16:02]:
> Hi
> 
> After commit 872c922 there is some trouble on PCI configuration
> access with Asus M4A785-M. This could apply to other amdfam10 too,
> although I have not yet received such reports.
> 
> As the commit message stated, I had discovered that in the beginning
> of ramstage all PCI configuration access used the IO (0xcf8) method
> even though Kconfig specified MMCONF_SUPPORT_DEFAULT which should
> imply all PCI config access is done with MMCONF unless IO is
> explicitly requested.

Not sure if this is relevant, but on i945 not all PCI devices are
visible in MMCONF space. So enabling MMCONF_SUPPORT_DEFAULT there will
break the system.

Stefan