Hi Jie,
On Tue, Jun 30, 2026 at 09:03:52AM +0800, Jie Gan wrote:
[...]
- How can you guarantee that a interconnect TraceNoC will never require ATID in the future?
From a hardware perspective, there is no fundamental difference between an itnoc and an AG TraceNoC. They use the same TraceNoC hardware implementation and share the same AMBA bus type. The distinction is purely functional: an itnoc is used for local trace aggregation within a subsystem, whereas an AG TraceNoC serves as the top-level aggregation point for the SoC.
I'm still not convinced that adding "arm,primecell-periphid" is the right approach.
From the description above, I'd expect either the hardware to expose bits in a register to distinguish these two module types, or as I suggested earlier, to use a DT property to indicate the module type (or whether ATID is required).
Or have you tried to detect the last tnoc on a path and allocate ID for it? (You can retrieve csdev->path).
Thanks, Leo