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| author | Brian J. Nemec <bnemec@chromium.org> | 2020-10-20 09:10:20 -0700 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2020-10-21 16:52:53 +0000 |
| commit | 5047df065dfede71f795c18d9f75cc8ef98d2017 (patch) | |
| tree | f35e3f71acc663a051a8fdb9df2dca007793e4e2 /extra | |
| parent | ef23cf615a0dcc853d373c6fc766c60032e9f9b3 (diff) | |
| download | chrome-ec-5047df065dfede71f795c18d9f75cc8ef98d2017.tar.gz | |
servo_updater: Add timeout on the pty flush
If the servo is in a loop where it sends output on a continuous basis,
the flush operation needs to eventually timeout. If the servo sends
commands out faster than the timeout provided to the expects() call,
it would never advance. This blocked the servo_updater from advancing.
BUG=b:162628581
TEST=Connect Servo_v4p1 to DUT validate servo_updater works
TEST=Modify Servo firmware to generate many console messages
in a loop. Validate that the flush operation succeeds and
servo updater still works.
Change-Id: I8c0e65a0733b4d4ee25a9f9c866aa2b863cb0e5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2487256
Reviewed-by: Matthew Blecker <matthewb@chromium.org>
Tested-by: Brian Nemec <bnemec@chromium.org>
Commit-Queue: Brian Nemec <bnemec@chromium.org>
Diffstat (limited to 'extra')
| -rw-r--r-- | extra/tigertool/ecusb/pty_driver.py | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/extra/tigertool/ecusb/pty_driver.py b/extra/tigertool/ecusb/pty_driver.py index 63df230e7e..e5ff043aad 100644 --- a/extra/tigertool/ecusb/pty_driver.py +++ b/extra/tigertool/ecusb/pty_driver.py @@ -14,10 +14,12 @@ import errno import fcntl import os import pexpect +import time from pexpect import fdpexpect # Expecting a result in 3 seconds is plenty even for slow platforms. DEFAULT_UART_TIMEOUT = 3 +FLUSH_UART_TIMEOUT = 1 class ptyError(Exception): @@ -76,9 +78,13 @@ class ptyDriver(object): """Flush device output to prevent previous messages interfering.""" if self._child.sendline('') != 1: raise ptyError('Failed to send newline.') - while True: + # Have a maximum timeout for the flush operation. We should have cleared + # all data from the buffer, but if data is regularly being generated, we + # can't guarantee it will ever stop. + flush_end_time = time.time() + FLUSH_UART_TIMEOUT + while time.time() <= flush_end_time: try: - self._child.expect('.', timeout=0.2) + self._child.expect('.', timeout=0.01) except (pexpect.TIMEOUT, pexpect.EOF): break except OSError as e: |