fix(native-usb): isolate two-pair transport and hand off read status in IRQ

tests/test_native_hub_log_native.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import shutil
+import signal
+import subprocess
+from pathlib import Path
+
+
+def test_native_logger_keeps_usb_interrupt_progress(tmp_path: Path) -> None:
+    root = Path(__file__).resolve().parents[1]
+    compiler = shutil.which("cc") or shutil.which("gcc")
+    assert compiler is not None, "a host C compiler is required"
+    (tmp_path / "probe_version.h").write_text(
+        "static const uint8_t probe_version_replies[PROBE_CONTROLLER_COUNT][16] = {{0}};\n"
+        "static const uint8_t probe_firmware_versions[PROBE_CONTROLLER_COUNT][12] = {{0}};\n"
+    )
+    executable = tmp_path / "native_hub_log_test"
+    subprocess.run(
+        [
+            compiler,
+            "-std=c11",
+            "-Wall",
+            "-Wextra",
+            "-Werror",
+            "-ffunction-sections",
+            "-fdata-sections",
+            "-DSWITCH2_PROBE_HUB=1",
+            "-DPROBE_CONTROLLER_COUNT=4",
+            "-DSWITCH2_PROBE_NEUTRAL_INPUT=1",
+            "-DSWITCH2_PROBE_TRACE_NATIVE_INPUT=1",
+            "-DSWITCH2_PROBE_USB_INIT=1",
+            "-DSWITCH2_PROBE_MEMORY=1",
+            "-DSWITCH2_PROBE_VERSION_REPLY=1",
+            f"-I{root / 'tests' / 'native_hub_stubs'}",
+            f"-I{root / 'src' / 'firmware'}",
+            f"-I{root / 'tools' / 'switch2_usb_probe'}",
+            f"-I{tmp_path}",
+            str(root / "tests" / "native_hub_log_test.c"),
+            "-Wl,--gc-sections",
+            "-o",
+            str(executable),
+        ],
+        check=True,
+        cwd=root,
+    )
+    subprocess.run([str(executable)], check=True, cwd=root)
+    for caller in ("core", "irq"):
+        rejected = subprocess.run(
+            [str(executable), caller], capture_output=True, check=False, cwd=root
+        )
+        assert rejected.returncode == -signal.SIGABRT, (
+            "unsafe concurrent log producer was accepted"
+        )