Re: [PATCH 10/10] ARM: shmobile: r8a7791: Add IPMMU DT nodes

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Magnus,

On Tuesday 16 December 2014 07:44:32 Magnus Damm wrote:
> On Tue, Dec 16, 2014 at 3:44 AM, Laurent Pinchart wrote:
> > On Monday 15 December 2014 14:07:52 Geert Uytterhoeven wrote:
> >> On Mon, Dec 15, 2014 at 1:13 AM, Laurent Pinchart wrote:
> >> > Add the seven IPMMU instances found in the r8a7791 to DT with a
> >> > disabled status.
> >> > 
> >> > Signed-off-by: Laurent Pinchart
> >> > <laurent.pinchart+renesas@ideasonboard.com>
> >> 
> >> The addresses and interrupt numbers look OK to me.
> >> However, my comment about the "0x800" offset is still valid.
> >> Shouldn't we have two register blocks, and let the driver use only the
> >> second one?
> >> 
> >> If you ignore, feel free to add my
> >> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > 
> > I don't want to ignore your comment, but I don't know what to do here :-/
> > The datasheet lacks detailed information about secure vs. non-secure mode
> > and how the two register sets are supposed to interoperate and be handled
> > by the operating system.
> 
> I don't know about that either.
> 
> But how about differences within R-Car Gen2 series so far? If there
> are known differences then perhaps we should use part number in the
> compatible string?

I haven't noticed differences between H2 and M2. V2 and E2 are extended with 
IOMMU performance monitoring registers, so a specific compatible string is 
needed.

"renesas,ipmmu-vmsa" should be the default fallback compatible string. I was 
thinking about playing with the newer SoCs first to see how the IOMMU react 
and then most likely add SoC-specific compatible strings.

-- 
Regards,

Laurent Pinchart