Hi Suzuki,
On Wed, Mar 20, 2019 at 01:52:58PM +0000, Suzuki K Poulose wrote:
>
>
> On 20/03/2019 12:38, Wanglai Shi wrote:
> > From: Leo Yan <[email protected]>
> >
> > Since CoreSight hardware topology can use a 'hidden' funnel in the
> > trace data path, this kind funnel doesn't have register for accessing
> > and is used by default from hardware design perspective. Below is an
> > example for related hardware topology:
> >
> > +------+ +------+
> > | cpu0 |->| ETM |-\
> > +------+ +------+ \-> +--------+ +-----+
> > ...... | Funnel |->| ETF |-\ Hidden funnel
> > +------+ +------+ /-> +--------+ +-----+ \ |
> > | cpu3 |->| ETM |-/ \ V
> > +------+ +------+ \-> +--------+
> > | Funnel |-> ...
> > +------+ +------+ /-> +--------+
> > | cpu4 |->| ETM |-\ /
> > +------+ +------+ \-> +--------+ +-----+ /
> > ...... | Funnel |->| ETF |-/
> > +------+ +------+ /-> +--------+ +-----+
> > | cpu7 |->| ETM |-/
> > +------+ +------+
> >
> > The CoreSight funnel driver only supports dynamic funnel with
> > registration register resource, thus it cannot support for the static
> > funnel case and it's impossible to create trace data path for this case.
> >
> > This patch is to extend CoreSight funnel driver to support both for
> > static funnel and dynamic funnel. For the dynamic funnel it reuses the
> > code existed in the driver, for static funnel the driver will support
> > device probe if without providing register resource and the driver skips
> > registers accessing when detect the register base is NULL.
> >
> > Signed-off-by: Leo Yan <[email protected]>
> > ---
>
> Suggested-by: Suzuki K Poulose <[email protected]>
Will add the tag in next version, and very appreciate you shared me
offline the replicator code for reference!
> > -static const struct amba_id funnel_ids[] = {
> > +static int static_funnel_probe(struct platform_device *pdev)
> > +{
> > + int ret;
> > +
> > + pm_runtime_get_noresume(&pdev->dev);
> > + pm_runtime_set_active(&pdev->dev);
> > + pm_runtime_enable(&pdev->dev);
> > +
> > + /* Static funnel do not have programming base */
> > + ret = funnel_probe(&pdev->dev, NULL);
> > +
> > + if (ret) {
> > + pm_runtime_put_noidle(&pdev->dev);
> > + pm_runtime_disable(&pdev->dev);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static const struct of_device_id static_funnel_match[] = {
> > + {.compatible = "arm,coresight-funnel"},
>
> There is a potential issue with re-using the "compatible" string
> already reserved for the normal programmable funnel. We may handle
> a programmable funnel as non-programmable one, which is not good.
>
> Do we need to use "arm,coresight-static-funnel" ?
This suggestion makes sense, will do this.
> Otherwise, looks good to me.
Thanks for reviewing.
Thanks,
Leo Yan
