Re: [PATCH v2 2/6] Documentation: devicetree: add bindings to support ARM MHU doorbells
From: Jassi Brar
Date: Thu Jul 06 2017 - 05:27:54 EST
On Thu, Jul 6, 2017 at 2:48 PM, Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
> Hi Jassi,
> On 06/07/17 07:28, Jassi Brar wrote:
>> On Wed, Jul 5, 2017 at 11:32 PM, Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
>>> I have posted the SCMI patches now,
>> I wish I was CC'ed on that. Now LKML seems too busy to forward it.
> Yes, my mistake, I should have cc-ed you.
>>> please let me know how to get
>>> both SCPI and SCMI working together with different doorbell bits on the
>>> same channel.
>> You say in the cover letter :
>> "Let me begin admitting that we are introducing yet another protocol to
>> achieve same things as many existing protocols like ARM SCPI, TI SCI,
>> QCOM RPM, Nvidia Tegra BPMP, and so on"
>> So SCMI is supposed to replace SCPI, SCI, RPM and BPMP or SCMI is
>> to be used for future platforms.
>> If SCPI and SCMI achieve the same, why have them both active simultaneously?
> Yes it may not be used, but the firmware might support both for backward
> compatibility. E.g. on Juno, we still may continue supporting SCPI while
> we transition to SCMI. So both old and new DTs must work.
Sure, but still there is no reason to have both SCMI and SCPI active
Either SCMI or SCPI should be populated by DT, not both.
>> Assuming there really is some sane excuse :-
> Yes as I mentioned above.
If you specify only one of SCPI/SCMI, you wouldn't need the shim arbitrator.