Re: [Fwd: Re: [PATCH 0/5]PCI: x86 MMCONFIG]

[Greg KH <gregkh@suse.de>]

On Thu, Dec 20, 2007 at 05:36:43PM -0500, Tony Camuso wrote:
> Greg KH wrote:
>> On Thu, Dec 20, 2007 at 01:25:57PM -0500, Tony Camuso wrote:
>> Any reason why these changes were never submitted to the upstream kernel
>> versions?  Or do you all just want to keep patching your newer releases
>> with this information forever?  :)
>
> I really don't know why these changes were never submitted to the
> upstream kernel versions".
>
> I was brought on the scene about six months ago as HP's on-site engineer
> at RH, and this was one of the things they wanted me to do.
>
> We wanted a solution that was more generic and could manage this
> problem preemptively, rather than using blacklists. Maintenance of
> blacklists is a bother and almost always done after a new system
> with this problem is discovered.
>
> Furthermore, blacklisting whole platforms to use legacy pci config
> penalizes any mmconfig-friendly buses in those platforms, particularly
> the pci express buses, and causes such platforms to be non-compliant
> with the pci expres spec.

Sure, I realize this, but it solves the problem in one way for broken
hardware, such that it at least allows it to work, right?  It also
provides a better incentive for the manufacturer to fix their bios,
which as you are on-site at HP, it would seem odd that they would just
not do that instead of trying to work around this in the kernel...

thanks,

greg k-h