[ericjuta]

Summary

Separate the opt-in T8122 GPU performance ceiling from its boot/sensor-failure cap, and expose the complete J615 SoC die sensor set.

Three commits:

1. hwmon: add J615's six GPU-family and six CPU die keys; require all twelve to be discovered before registering the zone.
2. drm/asahi: preserve the state-2 boot/failure cap even when asahi.t8122_pstate_cap=5 is requested. Off/hold cannot boost above the safe cap; lower requested ceilings still win. Add regression coverage for missing, failed, stale, stuck and implausible readings, pacing, hot/critical temperatures and recovery.
3. docs/tools: explain the guarded ceiling, qualification procedure and older-kernel warning; update one-shot help.

The default ceiling remains 2. Non-T8122 cap selection is unchanged. This also conservatively bounds T8122 boards without usable sensor feedback.

Validation

• rustc --edition=2021 --test tools/asahi/m3-runtime-tests.rs -o /tmp/j615-thermal-runtime-tests and execution: 24 passed on the rebased branch.
• bash -n tools/aurora-sep/air-gpu/air-gpu-oneshot.sh: passed.
• Existing running J615 custom kernel 7.2.11-dcpexp-thermal+, configured with asahi.t8122_pstate_cap=5 asahi.m3_thermal=on, logs runtime cap 5 -> 4 -> 3 -> 2 at 80.3–80.5 C, then recovery 2 -> 3 -> 4 -> 5 at 66.5–67.7 C. This is observed runtime behavior, not proof that the freshly rebased branch is the running binary.
• The newly rebased branch has not had a full kernel build/boot test. Sensor-failure behavior is covered by host tests, not injected hardware faults. No claim of calibrated temperatures or hardware safety certification.

Scope

Based on current integration/aurora (8eddf5a). Excludes existing display/brightness PRs #354, #356 and #357, local boot deployment scripts, and USB power workarounds. The intermittent USB-C -28/revalidation failure is unresolved and is not claimed fixed here.

[ericjuta]

Additional J615 hardware observations (2026-11-08): the currently running combined kernel is 7.2.11-dcpexp-usb-recovery-20261108, with asahi.t8122_pstate_cap=5 and asahi.m3_thermal=on. All nine locally modified thermal-related source/docs files are byte-for-byte identical between the earlier thermal working tree and this USB-recovery build tree. The installed Image matches the build Image by SHA-256; installed asahi/macsmc-hwmon module build IDs match the build artifacts. This is provenance for the combined local build, not a claim that the rebased PR branch was built or booted unchanged.

The current boot registered all 12 listed J615 die keys. Runtime logs show cap 2 -> 3 -> 4 -> 5 with cool readings, and 5 -> 4 -> 3 -> 2 with readings of 80.5–83.8 C; the firmware summary reports peak state 5. The user reports stable unplug/replug and lid-open/closed use on this combined kernel. No sensor-failure injection or sustained thermal qualification was performed in this audit.

Please keep the sensor/fallback correctness work separate from raising default performance limits. Review coordination with overlapping #135 is still needed, particularly explicit thermal-Off semantics. The all-keys requirement concerns the selected sensor list; it does not establish calibrated coverage of the hottest physical location, nor does it prevent an explicit partial sensor-list override. These observations do not establish hardware safety or qualify #317.