Re: [PATCH v2 08/11] of: Increase MAX_PHANDLE_ARGS

[Andreas Herrmann <andreas.herrmann-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>]

On Wed, Jan 29, 2014 at 11:59:12AM -0500, Suravee Suthikulanit wrote:
> On 1/29/2014 10:57 AM, Rob Herring wrote:
> >>> diff --git a/include/linux/of.h b/include/linux/of.h
> >>> >>index 276c546..24e1b28 100644
> >>> >>--- a/include/linux/of.h
> >>> >>+++ b/include/linux/of.h
> >>> >>@@ -67,7 +67,7 @@ struct device_node {
> >>> >>   #endif
> >>> >>   };
> >>> >>
> >>> >>-#define MAX_PHANDLE_ARGS 8
> >>> >>+#define MAX_PHANDLE_ARGS 16
> >> >
> >> >
> >> >Since the MMU-500 specify "Number of SMRs" upto 128 registers, shouldn't
> >> >this be changed to be able to support 128 StreamIDs as well?  Although I am
> >> >not sure if this would be too big to have on the stack per Rob's comment in
> >> >the previous patch set.
> > Do you actually need 128 now? If not, then we can deal with that when
> > we get there. There are lots of things in spec's that are not actually
> > implemented or supported.
> 
> Actually, we are using 32 on the AMD system. So, do you think we can set 
> this to 32 instead?

I think that's ok.

But are we really talking about number of SMRs or number of StreamIDs
per master device here? Ie. are you just having 32 SMRs for an SMMU on
your AMD system or do you have master devices which have 32 StreamIDs?

If it's just number of SMRs we don't need to modify this macro.


Andreas