Re: [arch-general] powernow-k8 fails to load with linux 3.7.2

Matthew Garrett
2013-01-18T17:17:53Z

On Fri, 2013-01-18 at 18:10 +0100, Borislav Petkov wrote:

> Well, actually, those CPUID bits are there for exactly that reason: to
> query them and enable software features. And this is one of the reasons
> CPUID is a ring 3 instruction: so that even userspace can use it.
>
> So, in a perfect world, udev should simply run CPUID, check the
> respective bits, and, if they're set, load the respective driver. That
> is, if it doesn't do it already.
>
> No need for additional code glue in the kernel or anywhere else.

We already have the additional code in the kernel - it means we can add
modaliases when new functionality gets added to the kernel, instead of
having to update udev as well. We /could/ have udev use outb and inb to
identify PCI devices as well, but it seems more reasonable to use the
information the kernel already has and exposes :)