Re: [PATCH v4 11/12] [RFC] firmware: arm_scmi: Add sync_cmds_atomic_replies transport flag

[Florian Fainelli <f.fainelli@gmail.com>]

On 8/24/2021 3:59 PM, Cristian Marussi wrote:
> A flag is added to let the transport signal the core that its handling of
> synchronous command messages implies that, after .send_message has returned
> successfully, the requested command can be assumed to be fully and
> completely executed on SCMI platform side so that any possible response
> value is already immediately available to be retrieved by a .fetch_reponse:
> in other words the polling phase can be skipped in such a case and the
> response values accessed straight away.
> 
> Note that all of the above applies only when polling mode of operation was
> selected by the core: if instead a completion IRQ was found to be available
> the normal response processing path based on completions will still be
> followed.

This might actually have to be settable on a per-message basis ideally 
since we may be transporting short lived SCMI messages for which the 
completion can be done at SMC time, and long lived SCMI messages (e.g.: 
involving a voltage change) for which we would prefer a completion 
interrupt. Jim, what do you think?
-- 
Florian