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

Suzuki K Poulose
2021-05-10T13:15:07Z

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