M2-USBCLK-01 physical result

2026-09-09, owner supplied out/m2-usbclk-01/{10,50}.jpg and reports no errors. Both photos identify M2-USBCLK-01 / Linux 6.18.0-y2-m2-usbclk1. Copies and hashes are retained in evidence-private/20260909-m2-usbclk-result/manifest.json.

10.jpg: 278033 bytes, SHA-256 b6c4aa3d9958147a81da0b70a52bd1ed3005c392a2cb00bc65c1db4350b822d6. 50.jpg: 330751 bytes, SHA-256 bd2d967a6a1cfb48f35c04659db24f1c97aace825cf641202fc39cc58cb01562. Inspection crops were used only to read the original photos; originals are retained.

Interpretation and limits

CONFIRMED: timer reporting is corrected and counts increase; the delta is 3885 interrupts over 38.85 kernel uptime seconds, consistent with CONFIG_HZ=100. These are kernel-derived times, not independent host-clock calibration.

The clock contract decodes PERI bit 10 clear (USB0 ungated), mux power-down bit 23 clear with selector 1, UNIVPLL USB reference enable bit 26 and main enable bit 0 set. PLL power bit 0 is set and isolation bit 1 clear (vendor mt_clkmgr.c PLL_PWR_ON / PLL_ISO_EN). Preserve unrelated bits, including the high PWR bit. This is one cached snapshot, not continuous clock monitoring or a measured frequency. VUSB remains reported enabled.

The source-backed next step can inspect the inherited USB MAC and digital PHY state without enabling clocks, changing analog trims or taking DMA ownership. MAC/PHY access itself remains untested until that candidate runs. Controller initialization, peripheral/VBUS behavior and DMA quiescence are still unresolved.

Associated candidate SHA-256 is 602080eb199f3a4be30082ee114dfeb97ef414e10d8ad4acf5d239f2096cd6ec. The owner supplied build-identifying photographs, not selected/flashed/readback hash confirmation. Host time, cable state and restoration outcome are unreported. M1 remains complete; #23/#27/#28 remain open. No USB logging or M2 exit is claimed.