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diff --git a/examples/device/usbtest/README.md b/examples/device/usbtest/README.md new file mode 100644 index 000000000..8fcc4ad36 --- /dev/null +++ b/examples/device/usbtest/README.md @@ -0,0 +1,94 @@ +# usbtest + +Device-side peer of the Linux kernel USB test pair: + +- `usbtest.ko` — host kernel module (`drivers/usb/misc/usbtest.c`) containing ~30 numbered + test cases over bulk/control/interrupt/isochronous transfers. +- `testusb` — userspace dispatcher (`tools/usb/testusb.c`) that tells the module which case + to run via usbfs ioctl. + +This example implements the Gadget-Zero style *source/sink* protocol on a vendor-specific +interface so the whole battery can exercise TinyUSB device controller drivers: + +- bulk IN = infinite source (usbtest pattern 0: all zeros) +- bulk OUT = infinite sink (data discarded) + +## Tiers + +The firmware advertises its capability tier in `bcdDevice` (`0x01TT`); the host script picks +the matching test battery automatically. + +| Tier | Capability | usbtest cases | +|------|------------|---------------| +| 1 | bulk source/sink | 0, 9, 10, 1–8, 11, 12, 24, 13, 29, 17–20, 27, 28 | +| 2 | + vendor control `0x5b`/`0x5c` (ctrl_out) | + 14, 21 | +| 3 | + interrupt source/sink | + 25, 26 | +| 4 | + isochronous source/sink | + 15, 16, 22, 23 | + +This example implements all four tiers using the vendor class with the interrupt +(`CFG_TUD_VENDOR_EP_INT_OUT/IN`) and isochronous (`CFG_TUD_VENDOR_EP_ISO_OUT/IN`) +endpoint pairs and altsetting support (`CFG_TUD_VENDOR_ALT_SETTINGS`): alt 0 +carries no endpoints, alt 1 the full source/sink set, per USB 2.0 5.6.3 (the host +usbtest driver selects alt 1 itself). + +## Test cases + +Directions are from the host's point of view: *write* = host→device (OUT endpoint, device +sinks and discards), *read* = device→host (IN endpoint, device sources zeros and the host +verifies every byte). All checking happens host-side in `usbtest.ko`; a case fails on a data +mismatch, an unexpected short packet/STALL, or a timeout. What each case stresses on the +device/DCD side: + +| # | Name | What it does / what it exercises | +|---|------|----------------------------------| +| 0 | NOP | ioctl round-trip sanity, no USB traffic — proves the interface bound with the right capability profile | +| 9 | ch9 subset | chapter-9 standard control requests (GET_DESCRIPTOR, GET_STATUS, SET/CLEAR_FEATURE, SET_INTERFACE, …) — the EP0 state machine, incl. status stages and ZLPs | +| 10 | queued control | many control URBs in flight at once — EP0 under sustained back-to-back SETUPs | +| 1 / 2 | bulk write / read | plain OUT sink / IN source streams of whole max-size packets — FIFO handling, multi-packet transfers | +| 3 / 4 | bulk write / read vary | same with transfer sizes varying per URB — short packets and packet-boundary edge cases | +| 5–8 | bulk sg write/read (+vary) | scatter-gather queued URBs — continuous packet pressure with no inter-URB gap; classic overflow/babble catcher | +| 11 / 12 | unlink reads / writes | URBs submitted then cancelled mid-flight — the device keeps streaming while the host aborts; DCD abort/cleanup paths | +| 24 | unlink queued writes | unlink from a deep OUT queue — same, under queue pressure | +| 13 | ep halt set/clear | SET_FEATURE(ENDPOINT_HALT), verify the endpoint really STALLs, then CLEAR_FEATURE and verify traffic resumes at DATA0 — stall must abort an armed transfer (and flush any loaded FIFO) | +| 29 | toggle clear | CLEAR_FEATURE(HALT) on a **non-halted** endpoint mid-traffic, purely to reset the data toggle — the DCD must reset DATA0 *without* disarming the queued transfer (historically the most common per-DCD bug in this battery) | +| 17 / 18 | bulk write / read unaligned | bulk streams from oddly-offset host buffers — host DMA-alignment path; the device sees normal traffic | +| 19 / 20 | bulk write / read premapped | bulk streams using host pre-mapped DMA buffers — another host memory path | +| 27 / 28 | bulk write / read perf | sustained maximum-throughput streams, reported in MB/s — real-time FIFO servicing under load | +| 14 | ctrl_out write/read | vendor EP0 request `0x5b` stores wLength bytes, `0x5c` reads them back, sizes varying — multi-packet control-OUT data stages and buffer persistence across requests | +| 21 | ctrl_out unaligned | same from odd host buffer offsets | +| 25 / 26 | int write / read | interrupt OUT sink / IN source at the descriptor's polling interval — interrupt endpoint arming and completion | +| 15 / 16 | iso write / read | isochronous OUT sink / IN source, one packet per (micro)frame with per-packet status — no handshake/retry, DATA0-only; the IN source must re-arm fast enough to make every frame deadline | +| 22 / 23 | iso write / read unaligned | same from odd host buffer offsets | + +Per-case iteration counts and sizes are chosen by `test/hil/usbtest.py` for the negotiated +speed (see its `PARAMS` table); the authoritative case implementations live in the kernel's +`drivers/usb/misc/usbtest.c`. + +## Running + +Use the host script (handles driver binding, per-case parameters, result parsing): + +```bash +python3 test/hil/usbtest.py --serial <board-uid> +``` + +Requirements on the host: `usbtest` kernel module (`CONFIG_USB_TEST`, `modprobe usbtest`), +the `testusb` binary built from kernel `tools/usb/testusb.c`, and sudo (usbfs ioctls + +driver bind/unbind). + +Manual runs are possible but beware `testusb` defaults: always pass explicit `-s`/`-v` +values that are multiples of 512 — the device streams whole max-size packets, so a +non-packet-aligned read length overflows (`-EOVERFLOW`), and never run bare `testusb -a` +(the default parameter set includes cases with invalid parameters and hour-long runtimes +at full speed). + +```bash +# bind: MUST use the 5-field form referencing Gadget Zero (0525:a4a0) so the +# dynamic id inherits its capability profile. A plain "cafe 4010" id leaves +# driver_info NULL, which usbtest_probe() dereferences -> kernel oops. +sudo modprobe usbtest +echo "cafe 4010 0 0525 a4a0" | sudo tee /sys/bus/usb/drivers/usbtest/new_id +# example: bulk write/read +sudo testusb -D /dev/bus/usb/<BBB>/<DDD> -t 1 -c 128 -s 1024 -v 512 +sudo testusb -D /dev/bus/usb/<BBB>/<DDD> -t 2 -c 128 -s 1024 -v 512 +``` |