Re: [PATCH 04/22] arm64: dts: qcom: hamoa: Reserve low IOVA range for Iris

[Bryan O'Donoghue]

On 07/08/2026 11:22, Vikash Garodia wrote:
> > > > I don't like the idea of this series, because it_again_ doesn't tell us
> > > > the truth about the hardware. This typicall ends up with bigger problems
> > > honestly...thats all the info i have about the vpu hardware that it
> > > restricts non pixel to DMA from the 0-600MB range. The same i have been
> > > trying for a year now
> > You are not honest here. You also know that there are secure streams,
> > which have to use their own IOMMU SIDs. And some of them, as far as I
> > remember, also have memory range restrictions.
> please read the commit description again, the answer is there.

So I don't necessarily get all of the detail out of the commit log myself.

Could you give some detail to address Dmitry's point.

The question as I read it is - are all of the other potential SIDs 
covered by this change ?

> > So, if we land these patches, how do extend it later to account for all
> > of that?
> forward looking design would be subnode, which we can land ontop of this
> series.

Yes it should be possible to branch to make subnodes work on-top of this 
- accepting that once this lands it becomes ABI and support for this 
method must be sustained, even after sub-nodes land.

---
bod