pcie-link's retrain check compared post-retrain speed against a port's
max capability without checking whether anything was actually seated
downstream. A switch downstream port with no card plugged in retrains
to zero lanes but still reports a reset-state speed, so it was
misreported as "retrained to Gen1, capable of Gen5" — indistinguishable
from a real degraded link.
Now a port that was already empty before the retrain is skipped (same
treatment as a disabled device: legitimately unpopulated slots are
common and shouldn't fail the check), while a device that answered
before the retrain and disappeared right after it still fails, with an
honest "no device detected downstream" message instead of a fabricated
speed reading.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
NVIDIA GPUs deliberately downclock PCIe to Gen1 at idle for power
saving, and applyPCIeLinkSpeedWarning fired on every idle collector
pass regardless - since component-status DB records never downgrade
(Record() only ever raises severity), one boot-time idle sample
permanently pinned pcie:gpu:nvidia to Warning for the rest of the
session even after every load-bearing GPU SAT test passed clean. Two
prior fixes (nvidia-smi-sourced link speed, pcie_aspm=off boot flag)
didn't hold up against this hardware/driver combination - see
bible-local/decisions/2026-08-24-pcie-gpu-gen1-idle-warning.md for the
full history.
Rather than add a downgrade path, stop writing an unverified status in
the first place: parseLspciDevice no longer calls
applyPCIeLinkSpeedWarning on the idle path. LinkSpeed/MaxLinkSpeed stay
populated as plain descriptive fields; only a verified-under-load
caller may now turn them into a status verdict.
Two new SAT targets provide that verified signal:
- pcie-link (platform/pcie_link_check.go): forces every enabled PCIe
device - not just GPUs - to retrain via the PCIe spec's Link Control
"Retrain Link" bit, then compares the negotiated speed against the
device's max. Covers NICs/HBAs/switches that have no bee-gpu-burn
equivalent load tool. Classifies by PCI class code + vendor ID, not
name substrings. Routes gpu_nvidia/gpu_amd/other sub-verdicts into
their own component-status keys so a degraded NIC never reads as a
GPU fault.
- nvidia-pcie-bandwidth (platform/nvidia_pcie_bandwidth.go): drives
real host<->device traffic via dcgmi diag -r nvbandwidth and
resamples link speed immediately after, independent of nvbandwidth's
own pass/fail.
Both wired into the task queue/webui the same way as nvidia-config
(routes, dispatch, priority, Validate page cards, Run All Check SAT).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Mikhail Chusavitin