fix(radio_planner): exempt UNLOCK_RADIO_ACCESS from the failsafe panic

[Mikefly123]

What

The radio planner's rp_callback() failsafe reboots the board (panic) if the current task has been RUNNING for more than 128 s. It already exempts RP_TASK_TYPE_LOCK_RADIO_ACCESS from this check, but was missing the same exemption for RP_TASK_TYPE_UNLOCK_RADIO_ACCESS.

Why

A lock task held open longer than the failsafe window (e.g. continuous RX under the raw RAC) keeps its original start_time_ms. When the client releases the lock, unlock_radio_access() retypes the still-RUNNING task from LOCK to UNLOCK before the engine processes it. The very next rp_callback() then evaluates the failsafe against that stale start_time_ms and panics — at the exact moment the client releases the lock. This produced a deterministic silent reboot any time a radio lock was held past 128 s.

The fix adds the same task-type exemption for RP_TASK_TYPE_UNLOCK_RADIO_ACCESS so the retype-on-release path is no longer misclassified as a hung task.

HWIL-validated as carried patch on PROVES FCB v5e.

Related: Open-Source-Space-Foundation/proves-core-reference#439

This is a candidate for true upstreaming to Lora-net/usp once validated further.

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Stack position: 1/2 — base of stack main <- #1 <- #2. See #2 for the next layer.

[coderabbitai]

📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes
  • Prevented the failsafe from triggering incorrectly when radio access unlock operations remain in progress beyond the expected time window.

Walkthrough

The radio planner’s failsafe callback now excludes both LOCK_RADIO_ACCESS and UNLOCK_RADIO_ACCESS tasks from the panic condition while they remain running.

Changes

Radio planner failsafe

Layer / File(s)	Summary
Update running-task failsafe exemptions smtc_rac_lib/radio_planner/src/radio_planner.c	The rp_callback logic now exempts UNLOCK_RADIO_ACCESS alongside LOCK_RADIO_ACCESS from triggering RP_FAILSAFE.

Estimated code review effort: 2 (Simple) | ~5 minutes

Poem

I’m a bunny guarding the radio gate,
Lock and unlock may both wait.
No false panic, no startled stare,
The failsafe now handles each with care.
Hop, hop—access flows just right!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the main fix: exempting UNLOCK_RADIO_ACCESS from the radio planner failsafe panic.
Description check	✅ Passed	The description explains the failsafe issue, the stale task timestamp, the fix, and its validation.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

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