Re: [PATCHv5 2/9] driver/core: populate devices in order for IOMMUs

[Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>]

On Fri, Nov 22, 2013 at 05:35:58PM +0000, Stephen Warren wrote:
> On 11/22/2013 12:41 AM, Grant Likely wrote:
> > It seems more that IOMMU attachment is closer to being a property of the
> > bus rather than a property of the device itself. In that context it
> > would make more sense for the bus device to hold off child device
> > registration or probing until the IOMMU is available. That keeps the
> > logic out of both the core code and the individual device drivers.
> 
> The bus structure that DT and Linux know about is the register bus.
> There's no reason that devices have to emit their master transactions
> onto that same bus, or onto only that same bus.

Agreed. Dave (CC'd) and I actually had a lot of discussion around the DT bus
abstractions last week and we ended up with a binding that looked sane enough
to start a meaningful discussion in this area.

Dave -- care to post what we came up with? It certainly has a bunch of
overlap with the IOMMU problems being discussed here.

Will