Hi,
On 04/03/2019 17:18, Mathieu Poirier wrote:
On Sat, 2 Mar 2019 at 06:00, Leo Yan leo.yan@linaro.org 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.
I back that. I have already merged the static and programmable replicators into one and this should be out here soon. So, I back the single driver approach for funnels.
Cheers Suzuki
Regards, Mathieu
[1]. https://elixir.bootlin.com/linux/latest/source/drivers/tty/serial/amba-pl011...