Re: [PATCH v2 2/6] Documentation: devicetree: add bindings to support ARM MHU doorbells

[Sudeep Holla <sudeep.holla@arm.com>]

On 06/07/17 15:37, Jassi Brar wrote:
> On Thu, Jul 6, 2017 at 3:03 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:

[...]

>>
>> I said it *may not be used*, currently it is used.
>>
> SCPI provides more than what SCMI currently does - dvfs, clock, sensor.

Not sure what you mean by that, but that's not true.

> I see no reason why you must have SCPI and SCMI both running.
> 

We can still have 2 different protocols using same MHU channel with
different doorbells, what's wrong with that ?

> And even then there is a solution - a shim arbitrator. Other
> platforms, those share a channel, do that. No big deal.
> 

Example please ? Please remember these protocols are generic and we
can't add any platform specific code into them.

>  BTW, I hope you realise that we need a 'transport layer' which will
> be the platform specific glue between mailbox controller specifics and
> the generic SCMI code.

Why ? Clearly you have not made a since technical argument so far as why
MHU doorbell is not correct way even when MHU specification is clearly
allows it. I have given example of ST mailbox which has this doorbell
kind of support.

> I see your confusion in the form of some issues in the SCMI
> implementation, please CC me on the next revision.
> 

Care to elaborate on what's my confusion or at-least what you think so ?

Also if you have concern on implementation, ok we can discuss further.
But can you make it clear as what your objections are for the doorbell
MHU binding. How will I get the bit assigned for different protocols
which are platform specific ? I still need some binding , right ?
-- 
Regards,
Sudeep