Re: [PATCH] Suspend and Resume Support for Intel IOMMU

Ingo Molnar
2009-02-18T17:20:08Z

* Linus Torvalds <torvalds@linux-foundation.org> wrote:

> On Wed, 18 Feb 2009, Fenghua Yu wrote:
> >
> > +static int vtd_enabled;
> ..
> > +static int iommu_resume(struct sys_device *dev)
> > +{
> ..
> > + if (!vtd_enabled)
> > + return 0;
>
> Hmm. Why do this?
>
> Wouldn't it be much more logical to only register the
> iommu_sysdev if the thing is enabled, rather than having an
> odd flag that gets tested at runtime?

The sysdev_class_register() could be done straight in
intel_iommu_init(), because that gets called by pci_iommu_init()
which is an fs_initcall() - so all the sysdev facilities should
be up and running already.

Ingo