On Sat, 2 Mar 2019 at 06:00, Leo Yan <leo.yan@xxxxxxxxxx> wrote:
>
> On Sat, Mar 02, 2019 at 09:45:22AM +0000, Shiwanglai wrote:
>
> [...]
>
> > > + /* Top internals */
> > > + funnel@ec031000 {
> > > + compatible = "arm,coresight-funnel", "arm,primecell";
> > > + reg = <0 0xec031000 0 0x1000>;
> > > + clocks = <&crg_ctrl HI3660_PCLK>;
> > > + clock-names = "apb_pclk";
> > > +
> > > + out-ports {
> > > + port {
> > > + top_funnel_out: endpoint {
> > > + remote-endpoint =
> > > + <&top_etf_in>;
> > > + };
> > > + };
> > > + };
> > > +
> > > + in-ports {
> > > + #address-cells = <1>;
> > > + #size-cells = <0>;
> > > +
> > > + port@0 {
> > > + reg = <0>;
> > > + top_funnel_in0: endpoint {
> > > + remote-endpoint =
> > > + <&cluster0_etf_out>;
> > > + };
> > > + };
> > > +
> > > + port@1 {
> > > + reg = <0>;
> >
> > Here should s/<0>/<1>; otherwise DTC will complain warning for mismatching between 'port@1' and 'reg = <0>'.
>
> > -- if reg set to 1, then there's no data output from cluster 1 to top.
>
> Thanks for the info, Wanglai. Now I see why write as it is.
>
> I can confirm if directly use your patch with perf with mainline
> kernel I can capture CoreSight trace data successfully on Hikey960
> board.
>
> But since this DT binding will introduce DTC warning, I personally
> think we can improve for this with below method:
>
> We can create a funnel node named "funnel_combo", and we don't need to
> specify register address range for it; and cluster 0 and cluster 1 will
> output to "funnel_combo" and "funnel_combo" will output to the top
> funnel. Thus the DT binding will write as below.
>
> To support for a funnel without any register address range (we have
> support replicator like this mode), we also need to extend the driver
> drivers/hwtracing/coresight/coresight-funnel.c.
>
> Mathieu, Mike, Suzuki, could you help confirm this is the right
> direction we should move forward to?
Leo, thanks for testing this out. Shiwanglai, please add Suzuki and
myself to future revision of this set - this will help you getting a
timely response for your work.
As Leo pointed out we already have support for replicators that don't
have a register map and the same thing should be done in this case.
But contrary to what was done for replicators, I think we should keep
the drivers in the same file as Russell did here[1]. That way we can
keep all things funnel at the same place and reduce the amount of
kernel configuration options.
Regards,
Mathieu
[1]. https://elixir.bootlin.com/linux/latest/source/drivers/tty/serial/amba-pl011.c#L2819
>
> ---8<---
> /* An invisible combo funnel between clusters and top funnel */
> funnel_combo {
> compatible = "arm,coresight-funnel";
> clocks = <&crg_ctrl HI3660_PCLK>;
> clock-names = "apb_pclk";
>
> out-ports {
> port {
> combo_funnel_out: endpoint {
> remote-endpoint =
> <&top_funnel_in>;
> };
> };
> };
>
> in-ports {
> #address-cells = <1>;
> #size-cells = <0>;
>
> port@0 {
> reg = <0>;
> combo_funnel_in0: endpoint {
> remote-endpoint =
> <&cluster0_etf_out>;
> };
> };
>
> port@1 {
> reg = <1>;
> combo_funnel_in1: endpoint {
> remote-endpoint =
> <&cluster1_etf_out>;
> };
> };
> };
> };
>
> /* Top internals */
> funnel@ec031000 {
> compatible = "arm,coresight-funnel", "arm,primecell";
> reg = <0 0xec031000 0 0x1000>;
> clocks = <&crg_ctrl HI3660_PCLK>;
> clock-names = "apb_pclk";
>
> out-ports {
> port {
> top_funnel_out: endpoint {
> remote-endpoint =
> <&top_etf_in>;
> };
> };
> };
>
> in-ports {
> #address-cells = <1>;
> #size-cells = <0>;
>
> port@0 {
> reg = <0>;
> top_funnel_in: endpoint {
> remote-endpoint =
> <&combo_funnel_out>;
> };
> };
> };
> };
>
> --->8---
>
> [...]
>
> Thanks,
> Leo Yan
