Litepcie ECP5 PHY — await upstream response and decide path-forward

[marcos-mendez]

What

Track the upstream response to PopSolutions Cooperative's LitePCIe
ECP5 PHY scoping outreach, and decide the path forward when feedback
arrives (or doesn't).

Background

On 2026-05-06 the cooperative dispatched two parallel public-facing
artefacts on the LitePCIe ECP5 PHY question:

1. A private outreach email from Marcos Méndez Quintero (m@pop.coop)
   to Florent Kermarrec (florent@enjoy-digital.fr).
2. A public scoping issue against enjoy-digital/litepcie (filed as
   a regular issue with [discussion] prefix because Discussions is
   disabled on that repo):
   [discussion] Lattice ECP5 PHY — scoping a contribution / day-1 recon shows multi-quarter scope enjoy-digital/litepcie#164

Both artefacts mirror the same content: a calibration request asking
upstream maintainers whether and how the cooperative should pursue an
ECP5 PHY contribution, given that the day-1 recon showed the work is
multi-quarter, not multi-sprint.

The full scoping evidence and decision record lives in the
contribution log:

• https://github.com/popsolutions/Stays/blob/main/docs/upstream-contributions/2026-05-05-litepcie-ecp5phy.md

Checkpoints and follow-up plan

• 2026-05-13 (one-week checkpoint): Agent 4 polls the upstream
  issue + Marcos checks email. If a maintainer response has landed,
  Agent 4 opens a follow-up PR on the contribution log moving status
  to maintainer-response-{accepted|rejected|deferred} and proposes
  next steps.
• 2026-05-20 (two-week escalation point): If no response on either
  channel by this date, escalate. Two reasonable paths:
  • Send a brief, polite second email (Marcos's call).
  • Begin sub-option 1c reconnaissance work (search for permissively
    licensed open soft PCIe stacks suitable for porting onto the
    ECP5 DCU) so the cooperative is not idle while awaiting reply —
    but only if Agent R + Marcos sign off, since 1c is multi-week
    even at the recon stage.

If a response lands earlier, accelerate the checkpoint accordingly.

Out of scope for this issue

• Replying to florent's email (Marcos handles that personally).
• Editing the historical outreach-draft file
  (docs/upstream-contributions/2026-05-05-litepcie-ecp5phy-outreach-draft.md).
• Drafting the sub-option 1c implementation plan today (premature
  without upstream dialogue feedback).

Definition of done

This issue closes when either:

• (a) Upstream responds and Agent 4 lands a follow-up PR moving the
  contribution log into a maintainer-response-* resolution state
  with a derived next-step plan, OR
• (b) Both the 2026-05-13 and 2026-05-20 checkpoints elapse with no
  response, the cooperative makes an explicit park / escalate
  decision (with Marcos + Agent R), and that decision is recorded in
  the contribution log.

Authored by Agent 4 (Open FPGA Upstream Contributions).