From ff57edb3e5e8d36b2783971924bf7373b4fc39bc Mon Sep 17 00:00:00 2001 From: hathach Date: Sat, 13 Jun 2026 23:35:35 +0700 Subject: hil: make serial write timeout fatal MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit pyserial's posix write() raises SerialTimeoutException after partial progress with the byte count lost, so the retry loop re-sent from the same offset and could duplicate bytes on the wire — surfacing as bogus data-mismatch failures that look like device firmware bugs. write_timeout is already a total per-call deadline, so the loop added duplication risk without extending the budget: write once and treat a timeout as fatal. Default bumped 2 -> 10 s to keep the old overall bound; HIL_SERIAL_WRITE_DEADLINE removed. The per-character CLI loops keep their existing pacing (the 2 ms sleep between single-byte writes already spaces them on the wire); no unbounded ser.flush()/tcdrain is added. Review follow-up for #3643 (hil_test.py l.257/264 findings). Co-Authored-By: Claude Fable 5 --- test/hil/hil_test.py | 29 +++++++++-------------------- 1 file changed, 9 insertions(+), 20 deletions(-) diff --git a/test/hil/hil_test.py b/test/hil/hil_test.py index c2ba34f02..aee59e05a 100755 --- a/test/hil/hil_test.py +++ b/test/hil/hil_test.py @@ -145,8 +145,7 @@ class HilConfig(TypedDict): CMD_TIMEOUT = int(os.getenv('HIL_CMD_TIMEOUT', '180')) POOL_TIMEOUT = int(os.getenv('HIL_POOL_TIMEOUT', '3000')) SERIAL_READ_TIMEOUT = float(os.getenv('HIL_SERIAL_READ_TIMEOUT', '5')) -SERIAL_WRITE_TIMEOUT = float(os.getenv('HIL_SERIAL_WRITE_TIMEOUT', '2')) -SERIAL_WRITE_DEADLINE = float(os.getenv('HIL_SERIAL_WRITE_DEADLINE', '10')) +SERIAL_WRITE_TIMEOUT = float(os.getenv('HIL_SERIAL_WRITE_TIMEOUT', '10')) def cmd_stdout_text(out: Any) -> str: @@ -247,24 +246,14 @@ def open_serial_dev(port: str): return ser -def serial_write_all(ser: serial.Serial, data: bytes, deadline: float = SERIAL_WRITE_DEADLINE): - total = 0 - end = time.monotonic() + deadline - - while total < len(data): - try: - written = ser.write(data[total:]) - except serial.SerialTimeoutException: - written = 0 - - if written: - total += written - continue - - if time.monotonic() >= end: - raise AssertionError(f'Serial write timeout after {deadline:.1f}s') - - time.sleep(0.01) +def serial_write_all(ser: serial.Serial, data: bytes): + # write_timeout is a total deadline for the whole call (pyserial keeps partial progress + # internally). A timeout means the device stopped draining — treat it as fatal: pyserial + # loses the partial-write count on raise, so retrying would duplicate bytes on the wire. + try: + ser.write(data) + except serial.SerialTimeoutException: + raise AssertionError(f'Serial write timeout after {SERIAL_WRITE_TIMEOUT:.1f}s') def read_disk_file(uid: str, lun: int, fname: str) -> bytes: -- cgit v1.3.1