Hi Marshall,
For example in Trinity, IIRC, consumer products in mobile packages had their IOMMUs fused off because of the power they'd sip. IOMMU wasn't considered a compelling feature for mobile products at that time.
Luckily mobile A10-5750M (although this is 15h Richland, slightly newer than Trinity) found in G505S - has a functional IOMMU. H owever it wasn't working at proprietary UEFI - only with coreboot. Thank you very much for your explanation, and especially
let me just end with that's definitely not how I remember the discussions for either of those two features
note.
please refrain from posting baseless speculations on this mailing list
Well, I just wanted someone to confirm or deny it. No harm from a "baseless speculation" if it is disproved at the next letter. Thanks to Marshall's letter, now I know that the return of IOMMU to 16h Puma together with the introduction of AMD PSP - is just a pure coincidence.
Best regards, Mike Banon