util: introduce uart stress tester

This script repeats a console command on target UARTs, and collects the
output. It checks whether there are any lost characters or patterns are
corrupted.

BUG=b:131340067
BRANCH=None
TEST=manually ran this script on scarlet with suzy-Q.

$ ./util/uart_stress_tester.sh -h
usage: uart_stress_tester.sh [flags]
example:
  uart_stress_tester.sh --pty /dev/ttyUSB0 --min_char 100000
  uart_stress_tester.sh --pty="/dev/ttyUSB0 /dev/ttyUSB2"
flags:
  --pty:  List of UART device path(s) to test (default: '')
  --min_char:  Minimum number of characters to generate. \
(default: 40000)
  -h,--[no]help:  show this help (default: false)

$ echo 'chan save' > /dev/ttyUSB0
$ echo 'chan save' > /dev/ttyUSB2
$ echo 'chan 0' > /dev/ttyUSB0
$ echo 'chan 0' > /dev/ttyUSB2
$ ./util/uart_stress_tester.sh --pty="/dev/ttyUSB0 /dev/tty/USB1 \
/dev/ttyUSB2"
INFO    : ChromeOS UART stress test starts.
INFO    : UART devices: /dev/ttyUSB0 /dev/ttyUSB2 /dev/ttyUSB1
.....
INFO    : /dev/ttyUSB0: 0 lost / 48785 : 0 %
ERROR   : /dev/ttyUSB2: 19444 lost / 41965 : 46.3 %
ERROR   : /dev/ttyUSB1: 16768 lost / 40425 : 41.4 %

INFO    : Test files are in /tmp/uart_stress_tester.sh_latest
ERROR   : FAIL

Change-Id: Iedd8c9a62e089fde8894ee93329ee9f4a31bb3e7
Signed-off-by: Namyoon Woo <namyoon@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1586581
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Commit-Queue: Vadim Bendebury <vbendeb@chromium.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/util/presubmit_check.sh b/util/presubmit_check.sh
index b11c8dec47..e8a0f47506 100755
--- a/util/presubmit_check.sh
+++ b/util/presubmit_check.sh
@@ -19,6 +19,8 @@ for dir in $unittest_dirs; do
 done
 # Filter out flash_ec since it's not part of any unit tests.
 changed=$(echo "${changed}" | grep -v util/flash_ec)
+# Filter out uart_stress_tester.sh
+changed=$(echo "${changed}" | grep -v util/uart_stress_tester.sh)
 # Filter out this file itself.
 changed=$(echo "${changed}" | grep -v util/presubmit_check.sh)
 if [[ -n "${changed}" ]]; then