Re: [PATCHv7 2/5] mailbox: Introduce framework for mailbox

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

On 20/06/14 17:30, Jassi Brar wrote:
> On 20 June 2014 21:37, Sudeep Holla <sudeep.holla@arm.com> wrote:
>>
>> As I mentioned in the other mail, suppose there's one channel and multiple
>> users
>> of it. Each have to acquire the channel, and from then any data received
>> will
>> be sent to the client. But what is the async data from remote is not for the
>> client currently holding the channel. I also gave the example.
>>
>> If the remote is the process that controls power managements and allows you
>> to
>> set the thermal bounds. If those limits are crossed, it sends any interrupt
>> to
>> notify that, while the controller can be busy handling some other
>> request(say
>> DVFS).
>>
> Multiple clients of a single mailbox channel asks for a single
> 'server' type shim client that simply forwards requests to remote on
> behalf of clients but filter out async notifications from replies
> coming in from remote. In your case, your 'thermal' client driver will
> register itself with the shim server for 'thermal' type async
> notifications. The shim server holds the mailbox channel for whole of
> its lifetime so you never miss the thermal event.
>

OK thanks for clarifying this. I too had same understanding, just wanted to 
cross check and convince myself the need of shim layer.

Regards,
Sudeep