Re: [PATCH] dt-binding: remoteproc: Document generic properties

From: Suman Anna
Date: Thu Sep 08 2016 - 14:32:32 EST

Hi Rob,

On 09/08/2016 11:50 AM, Rob Herring wrote:
> On Fri, Sep 02, 2016 at 04:45:45PM -0500, Suman Anna wrote:
>> On 08/12/2016 05:42 PM, Bjorn Andersson wrote:
>>> On Fri 12 Aug 11:34 PDT 2016, Rob Herring wrote:
>>>> On Wed, Aug 10, 2016 at 10:37:02AM -0700, Bjorn Andersson wrote:
>>>>> This documents the generic properties "rprocs" and "rproc-names", used
>>>>> for consumer drivers to reference a remoteproc node.
>>>> How do you intend to use this? I wonder if it would not be better to
>>>> expose a remote proc with existing bindings for a particular purpose
>>>> (e.g. clocks, resets, etc.) rather than a generic connection. The client
>>>> side would have to have specific knowledge as to what functions the
>>>> remote proc provides.
>>> The remoteproc node represents the mechanism and resources needed to
>>> control the life cycle a co-processor, e.g. loading, booting, shutting
>>> gown a video encoder/decoder.
>>> The proposed reference allows a separate thingie to assert control of
>>> the life cycle of that co-processor.
>>> I acknowledge that in some cases there is a fine line between what is
>>> the life cycle management and what is the actual functionality
>>> implemented by that remote processor. But as the remoteproc mechanism is
>>> reusable between various use cases I think it makes sense to not describe
>>> them as one unit.
>> What's the current state of this patch, not officially acked yet right?
> Bjorn and I have discussed some, but probably needs more discussion.
> This binding alone is simple enough, but I want to understand better how
> it will be used and digesting all the QCom h/w is not simple.

OK, thanks. The binding has no bearing on Qcom h/w though.

>> While we are at this, can we agree upon an alias stem name as well, we
>> can stick to "rproc". Otherwise, I can submit an incremental patch on
>> top of this along with the code that adds an API to retrieve it for
>> client users.
> Any alias for this will be NAKed. My position on aliases is well
> documented.

Hmm, I don't have the complete background/history on your stance. I do
have a need for identifying an exact remoteproc instance. How do you
propose I do that without aliases, and without adding a non-hw related
property to the DTS node? Like for example, we have 8 identical DSPs on
Keystone 2 Hawking SoCs, and I need to construct a firmware name based
on the instance id, and I cannot do this based on probe order.