Re: [PATCH v1 3/3] coresight-tpda: Optimize the function of reading element size

[Tao Zhang]

On 7/8/2024 11:49 PM, Suzuki K Poulose wrote:
> On 05/07/2024 09:51, Tao Zhang wrote:
> > Since the new funnel device supports multi-port output scenarios,
> > there may be more than one TPDM connected to one TPDA. In this
> > way, when reading the element size of the TPDM, TPDA driver needs
> > to find the expected TPDM corresponding to the filter source.
> > When TPDA finds a TPDM or a filter source from a input connection,
> > it will read the Devicetree to get the expected TPDM's element
> > size.
> >
> > Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
> > ---
> >   drivers/hwtracing/coresight/coresight-tpda.c | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-tpda.c 
> > b/drivers/hwtracing/coresight/coresight-tpda.c
> > index 52b0201090fb..fc5a4e46cf5d 100644
> > --- a/drivers/hwtracing/coresight/coresight-tpda.c
> > +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> > @@ -110,9 +110,12 @@ static int tpda_get_element_size(struct 
> > tpda_drvdata *drvdata,
> >               csdev->pdata->in_conns[i]->dest_port != inport)
> >               continue;
>
>
> > -        if (coresight_device_is_tpdm(in)) {
> > +        if (coresight_device_is_tpdm(in)
> > +            || csdev->pdata->in_conns[i]->filter_src_dev) {
>
> How can we assume that the filter-source device is always TPDM ?
> It may be true for your test board, but driver must handle all
> possible cases. I would rather prefer:

Got it. I will update in the next patch series.


Best,

Tao

> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c 
> b/drivers/hwtracing/coresight/coresight-tpda.c
> index bfca103f9f84..b1d6f1dd60e3 100644
> --- a/drivers/hwtracing/coresight/coresight-tpda.c
> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> @@ -110,6 +110,13 @@ static int tpda_get_element_size(struct 
> tpda_drvdata *drvdata,
>                     csdev->pdata->in_conns[i]->dest_port != inport)
>                         continue;
>
> +               /*
> +                * If this port is tied to a source device,
> +                * jump to that directly.
> +                */
> +               if (csdev->pdata->in_conns[i]->filter_src)
> +                       in = csdev->pdata->in_conns[i]->filter_src;
> +
>                 if (coresight_device_is_tpdm(in)) {
>                         if (drvdata->dsb_esize || drvdata->cmb_esize)
>                                 return -EEXIST;
>
>
> Suzuki