[rohanmathew05]

Resolves the # FIXME: Switch to LiteXModule. on stream.Converter.

Problem with a one-word switch
Changing only Module -> LiteXModule makes Converter inherit AutoCSR/AutoDoc.
Converter.cls stores the converter class itself (e.g. _DownConverter), not an
instance. When a parent module collects its CSRs (e.g. VideoFrameBuffer, which holds
self.conv = stream.Converter(...)), the gatherer finds get_csrs on that class and
calls it without an instance:

TypeError: gatherer() missing 1 required positional argument: 'self'

So any SoC with a video framebuffer would fail to build.

Fix
Exclude cls from collection with autocsr_exclude = {"cls"} and
autodoc_exclude = {"cls"} (AutoCSR and AutoDoc each have their own exclude set).

Tests

• New test_converter_in_autocsr_parent (a parent module with a CSR and a Converter):

  • master: passes
  • Module -> LiteXModule only: fails with the TypeError above
  • this PR: passes

• test_stream, test_stream_pipeline, test_byte_enable, test_video,
  test_video_terminal: OK.

• Elaborated with --no-compile and compared the generated Verilog with master:

  • litex_sim (VexRiscv, SDRAM, Ethernet, video framebuffer, SD card)
  • KC705 (Ethernet, PCIe)
  • KCU105 (Ethernet, PCIe, SD card)

  Logic identical; only the hierarchy-tree comment order differs, which also
  varies between two runs of master.

• Elaboration only, no hardware.

Written with help from Claude Code (AI agent), reviewed and supervised by me.

[enjoy-digital]

Thanks @rohanmathew05, this looks good. I'll just wait a bit before merging to see if we should make the error more explicit and avoid this silent potential issue in the future.

[enjoy-digital]

Thanks @rohanmathew05 for the analysis and the fix. Closing this one in favor of #2763, which fixes the root cause in the gatherers instead of working around it here: AutoCSR/AutoDoc/CSRBankArray now skip class references (so the autocsr_exclude/autodoc_exclude lines are no longer needed), and CSRs held by a plain Migen Module without AutoCSR now raise an explicit error instead of being silently dropped. #2763 also includes the Converter switch to LiteXModule and your test scenario (credited in the PR). Thanks again!

[rohanmathew05]

Yes, I agree. Fixing it in the gatherers makes more sense. I'll keep that in mind for the future. Thanks!