Re: [PATCH v1 0/3] coresight: Support for building more coresight paths

[Suzuki K Poulose <suzuki.poulose@arm.com>]

Hi Tao

On 10/05/2021 12:05, Tao Zhang wrote:
> We are trying to achieve more types of Coresight source devices.
> For example, we have a type of coresight source devic named TPDM.
> In the process of using, sometimes mulitiple TPDMs need to be
> connected to the different input ports on the same funnel.
> Meanwhile, these TPDMs also need to output from different
> ports on the funnel.
> But, at present the Coresight driver assumes
> a) Only support Coresight source type ETM, ETR and ETF

Did you mean ETM and STM here ? ETR & ETF are not source types, rather
they are SINK.


> b) Funnels only support mulitiple inputs and one output
> Which doesn't help to add the above feature for our new Coresight
> source device TPDM. So, in order to accommodate the new device,
> we develop the following patches.

Where is the TPDM driver ? Could you give us a rough idea of the 
behavior in terms of the input / output ?


> a) Add support more types of Coresight source devices.

Which ones ? where is the code ?

> b) Add support for multiple output ports on funnel and the output
> ports could be selected by Corsight source.

Does the "TPDM" require programming to switch these output or are these 
"static" ?

Is this something that can be avoided by having a "fake" 
static-replicator in the path ?

e.g,              TPDM
	 ________________________________________________
  In0	|						|  -> Out0
  In1	|   Static-Funnel   -> Static-Replicator	|  -> Out1
  In2	|						|  -> Out2
	 ________________________________________________


Is this something that can be solved ? Again, please give a brief
description of the TPDM device and the driver code in the series to
give us a complete picture of what you are trying to do.

Reviewing some changes without having the full picture is not going to 
be helpful.

Suzuki