RE: [PATCH V3 2/2] firmware: arm_scmi: add smc/hvc transport

From: Peng Fan
Date: Fri Feb 28 2020 - 21:08:05 EST


Hi Sudeep,

> Subject: Re: [PATCH V3 2/2] firmware: arm_scmi: add smc/hvc transport
>
> On Wed, Feb 26, 2020 at 03:12:51PM +0800, peng.fan@xxxxxxx wrote:
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > Take arm,smc-id as the 1st arg, and protocol id as the 2nd arg when
> > issuing SMC/HVC. Since we need protocol id, so add this parameter
>
> And why do we need protocol id here ? I couldn't find it out myself.
> I would like to know why/what/how is it used in the firmware(smc/hvc
> handler). I hope you are not mixing the need for multiple channel with
> protocol id ? One can find out id from the command itself, no need to pass it
> and hence asking here for more details.

When each protocol needs its own shmem area, we need let firmware
know which shmem area to parse the message from. Without protocol
id, firmware not know which shmem area should use. Hope this is clear.

Thanks,
Peng.

>
> --
> Regards,
> Sudeep