Re: [patches] [patch 3/5] x86: Add PCI extended config space access for AMD Barcelona

Andi Kleen
2007-09-03T10:16:36Z

> But it is needed for some devices for full functionality.

Examples? I can only think of PCI express error reporting, which
few drivers implement anyways and isn't really a show stopper
if it doesn't work. Besides I would be surprised if it even works
on the cheap desktop boards which have MCFG less BIOS.

> E.g. for perfmon (family 0x10/extended inerrupts) extended config space
> access is a prerequisite.

How so?

>
> IMHO it is best to try to use MMCONFIG if it's working and to use
> a fallback (e.g. CF8 ECS access for family 0x10) if available.

We only put in workarounds if there is a serious problem otherwise (e.g. not
booting etc.). I just don't see this here.

-Andi