Re: [RFC PATCH 00/11] : media: iris: Migrate iommus to iris sub nodes

[Dmitry Baryshkov]

On Fri, Jul 10, 2026 at 07:32:35PM +0530, Vikash Garodia wrote:
> 
> On 7/10/2026 7:08 PM, Bryan O'Donoghue wrote:
> > On 10/07/2026 14:36, Vikash Garodia wrote:
> > > > What's the addressable range with sub-nodes ?
> > > > 
> > > > The original problem you were trying to solve was the total addressable
> > > > size - this other problem here segmenting the linear allocation space is
> > > > adjacent but not the same thing.
> > > > 
> > > > Without digging through all of the patches here - my question is does
> > > > the original sub-node addressable space problem get resolved in your
> > > > proposal here ?
> > > The proposal solves both the problem we have so far - total addressable
> > > size as well as which segment (or range) in that is_not_ addressable.
> > 
> > So if I can distill this.
> > 
> > You're proposing two objects in the DT one for each relevant IOMMU SID
> > and then the driver will register two different devices to get the full
> > range addresses ?
> 
> yes, alongwith the _non_ addressable range specific to that object, to avoid
> the device crash.

If one of the subtypes can address the whole range, why do we need a
separate subnode and a separate device for it?

-- 
With best wishes
Dmitry