[PATCH v2 08/11] of: Increase MAX_PHANDLE_ARGS

[Rob Herring]

On Thu, Jan 30, 2014 at 11:45 AM, Andreas Herrmann
<andreas.herrmann at calxeda.com> wrote:
> On Wed, Jan 29, 2014 at 12:26:35PM -0500, Suravee Suthikulanit wrote:
>> On 1/29/2014 11:16 AM, Andreas Herrmann wrote:
>> > 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.
>
>> I am referring to the case where each mmu-master can have upto 32 streamID.
>
> Rob,
>
> Do you agree on increasing MAX_PHANDLE_ARGS to 32?

Yes, but more than that will require a closer look. Please get this
into next early in the cycle.

> Or should this be done when someone (e.g. Suravee) submits a DTS
> update with an SMMU node description containing more than 16 stream
> IDs for a master device?

Well, I am inclined to not care having seen no upstream activity for
AMD's platform.

Rob