Speaker
Description
To support RISC-V E-trace/N-trace components in ACPI, we propose using the Device Graph UUID defined in the DSD Guide, aligned with how similar topologies are described on other architectures. Beyond discussing the proposal itself and how it should appear in the ACPI namespace, we also want feedback on implementation strategy.
Today, ACPI fwnode graph handling does not interpret Device Graph UUID data, so trace drivers parse ACPI graph links in-driver. We have a PoC with that approach, but it duplicates logic, raises long-term maintenance cost, and keeps DT and ACPI paths separate instead of reusing common fwnode_graph_* helpers.
Our proposal is to extend ACPI fwnode graph support, so Device Graph UUID data is translated into standard fwnode_graph_* operations. This allows shared trace-driver code across DT and ACPI, reduces duplication, and scales better as additional architectures adopt this representation.
We plan to post an RFC series before the conference so maintainers and subsystem stakeholders can review concrete patches and align on direction.