Re: [PATCH 3/4] dt-bindings: iommu/arm, smmu: add compatible string for Marvell
From: Rob Herring
Date: Thu Oct 18 2018 - 16:48:05 EST
On Mon, Oct 15, 2018 at 02:11:52PM +0100, Robin Murphy wrote:
> On 15/10/18 13:00, hannah@xxxxxxxxxxx wrote:
> > From: Hanna Hawa <hannah@xxxxxxxxxxx>
> > Add specific compatible string for Marvell usage due errata of
> > accessing 64bit registers of ARM SMMU, in AP806.
> > AP806 SOC use the generic ARM-MMU500, and there's no specific
> > implementation of Marvell, this compatible is used for errata only.
> Given that, I think something more specific like:
> "marvell,ap806-smmu", "arm,mmu-500";
> would be most appropriate. Otherwise, if some future Marvell SoC were to
> ever come out with a *different* MMU-500 integration problem, you'd already
> have painted yourself into a corner.
> Alternatively (or additionally), we could perhaps consider a separate
> property like "marvell,32bit-config-access", to mirror the existing handling
> of the secure integration bug.
The former please. We have learned our lesson there (though for some
reason, that was the *only* SMMU problem in Calxeda Midway ;) ).