Diagnostic query: Unexpected kernel panic on macOS Sequoia 15.1 after waking (1794676869)

[Ethan Carter]

Following the recent point release update, my system has encountered intermittent sleep/wake panics. The panic log cites IOPlatformPluginFamily and AppleThunderboltNHI assertions.

I have already tested clearing NVRAM, booted in Safe Mode to isolate third-party kexts, and disabled Power Nap. Has anyone isolated whether this is linked to external DisplayPort docks or an APFS snapshot indexing bottleneck?

[Owen Parker]

Thunderbolt/DisplayPort Dock Power Delivery & Firmware Path: The AppleThunderboltNHI assertion strongly implicates the Thunderbolt/USB4 controller failing to re-enumerate the PCIe tunnel or DisplayPort alt-mode link during the D0 transition. Verify the dock’s PD controller firmware (via vendor utility) and check ioreg -lw0 | grep -i "thunderbolt|nhi|pcitunnel" for AppleThunderboltNHIType3 link training failures. Temporarily disable “Wake for network access” and “Power Nap” via sudo pmset -a tcpkeepalive 0 powernap 0 to isolate whether the dock’s auxiliary power rail is dropping below the NHI controller’s hold-up voltage during dark wake.

iPhone 14 Pro | Apple Watch Series 10 | MagSafe Duo

Denver, CO | "Let humid USB-C ports air dry — never reach for rice."

[Hannah Brooks]

APFS Snapshot / mds Indexing Contention on Wake: While APFS snapshot metadata stalls (com.apple.apfs.fsck or backupd) rarely trigger IOPlatformPluginFamily panics directly, a concurrent mds/mdworker storm indexing a mounted Time Machine snapshot volume during the AppleThunderboltNHI re-enumeration window can starve the power management workloop. Run sudo log show --predicate 'eventMessage contains "AppleThunderboltNHI" or eventMessage contains "IOPlatformPlugin"' --last 24h --style syslog to correlate the panic timestamp with mds CPU spikes; exclude backup volumes from Spotlight (mdutil -i off /Volumes/Backup) and validate snapshot integrity via tmutil verifychecksums /path/to/snapshot.

MacBook Air M2 (16GB / 512GB) | iPad mini 7

Portland, OR | "Export solved community threads to PDF while they load."

[Liam O’Connor]

IOPlatformPluginFamily PMIC/SMC Handoff & Hibernate Mode Mismatch: The panic indicates the Platform Plugin (X86PlatformPlugin or AppleARMPlatformPlugin) received an invalid P-state/LPM request from the SMC/PMIC during the wake vector, often triggered by a stale hibernatemode setting conflicting with Sequoia’s updated sleep semantics. Confirm pmset -g custom | grep -E "hibernatemode|standby|autopoweroff"; force sudo pmset -a hibernatemode 3 standby 1 autopoweroff 1 (Intel) or ensure hibernatemode 3 is not forced on Apple Silicon (default is 0x80/standby). Reset the SMC/PMIC state via full shutdown + Left Shift+Control+Option+Power (10s) or Apple Silicon power cycle (30s unplugged) to clear stale thermal/P-state tables.

iMac 24″ M3 (16GB) | HomePod mini Stereo Pair

Dublin, IE | "Clean Wi-Fi multicast fixes half of AirPlay drops."

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