Re: [PATCH net-next 9/9] selftests: ptp: Add Physical Hardware Clock test

[Vladimir Oltean <olteanv@gmail.com>]

On Mon, 3 Jun 2019 at 15:25, Ido Schimmel <idosch@idosch.org> wrote:
>
> From: Shalom Toledo <shalomt@mellanox.com>
>
> Test the PTP Physical Hardware Clock functionality using the "phc_ctl" (a
> part of "linuxptp").
>
> The test contains three sub-tests:
>   * "settime" test
>   * "adjtime" test
>   * "adjfreq" test
>
> "settime" test:
>   * set the PHC time to 0 seconds.
>   * wait for 120.5 seconds.
>   * check if PHC time equal to 120.XX seconds.
>
> "adjtime" test:
>   * set the PHC time to 0 seconds.
>   * adjust the time by 10 seconds.
>   * check if PHC time equal to 10.XX seconds.
>
> "adjfreq" test:
>   * adjust the PHC frequency to be 1% faster.
>   * set the PHC time to 0 seconds.
>   * wait for 100.5 seconds.
>   * check if PHC time equal to 101.XX seconds.
>
> Usage:
>   $ ./phc.sh /dev/ptp<X>
>
>   It is possible to run a subset of the tests, for example:
>     * To run only the "settime" test:
>       $ TESTS="settime" ./phc.sh /dev/ptp<X>
>
> Signed-off-by: Shalom Toledo <shalomt@mellanox.com>
> Reviewed-by: Petr Machata <petrm@mellanox.com>
> Signed-off-by: Ido Schimmel <idosch@mellanox.com>
> ---
>  tools/testing/selftests/ptp/phc.sh | 166 +++++++++++++++++++++++++++++
>  1 file changed, 166 insertions(+)
>  create mode 100755 tools/testing/selftests/ptp/phc.sh
>
> diff --git a/tools/testing/selftests/ptp/phc.sh b/tools/testing/selftests/ptp/phc.sh
> new file mode 100755
> index 000000000000..ac6e5a6e1d3a
> --- /dev/null
> +++ b/tools/testing/selftests/ptp/phc.sh
> @@ -0,0 +1,166 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +
> +ALL_TESTS="
> +       settime
> +       adjtime
> +       adjfreq
> +"
> +DEV=$1
> +
> +##############################################################################
> +# Sanity checks
> +
> +if [[ "$(id -u)" -ne 0 ]]; then
> +       echo "SKIP: need root privileges"
> +       exit 0
> +fi
> +
> +if [[ "$DEV" == "" ]]; then
> +       echo "SKIP: PTP device not provided"
> +       exit 0
> +fi
> +
> +require_command()
> +{
> +       local cmd=$1; shift
> +
> +       if [[ ! -x "$(command -v "$cmd")" ]]; then
> +               echo "SKIP: $cmd not installed"
> +               exit 1
> +       fi
> +}
> +
> +phc_sanity()
> +{
> +       phc_ctl $DEV get &> /dev/null
> +
> +       if [ $? != 0 ]; then
> +               echo "SKIP: unknown clock $DEV: No such device"
> +               exit 1
> +       fi
> +}
> +
> +require_command phc_ctl
> +phc_sanity
> +
> +##############################################################################
> +# Helpers
> +
> +# Exit status to return at the end. Set in case one of the tests fails.
> +EXIT_STATUS=0
> +# Per-test return value. Clear at the beginning of each test.
> +RET=0
> +
> +check_err()
> +{
> +       local err=$1
> +
> +       if [[ $RET -eq 0 && $err -ne 0 ]]; then
> +               RET=$err
> +       fi
> +}
> +
> +log_test()
> +{
> +       local test_name=$1
> +
> +       if [[ $RET -ne 0 ]]; then
> +               EXIT_STATUS=1
> +               printf "TEST: %-60s  [FAIL]\n" "$test_name"
> +               return 1
> +       fi
> +
> +       printf "TEST: %-60s  [ OK ]\n" "$test_name"
> +       return 0
> +}
> +
> +tests_run()
> +{
> +       local current_test
> +
> +       for current_test in ${TESTS:-$ALL_TESTS}; do
> +               $current_test
> +       done
> +}
> +
> +##############################################################################
> +# Tests
> +
> +settime_do()
> +{
> +       local res
> +
> +       res=$(phc_ctl $DEV set 0 wait 120.5 get 2> /dev/null \
> +               | awk '/clock time is/{print $5}' \
> +               | awk -F. '{print $1}')
> +
> +       (( res == 120 ))
> +}
> +
> +adjtime_do()
> +{
> +       local res
> +
> +       res=$(phc_ctl $DEV set 0 adj 10 get 2> /dev/null \
> +               | awk '/clock time is/{print $5}' \
> +               | awk -F. '{print $1}')
> +
> +       (( res == 10 ))
> +}
> +
> +adjfreq_do()
> +{
> +       local res
> +
> +       # Set the clock to be 1% faster
> +       res=$(phc_ctl $DEV freq 10000000 set 0 wait 100.5 get 2> /dev/null \
> +               | awk '/clock time is/{print $5}' \
> +               | awk -F. '{print $1}')
> +
> +       (( res == 101 ))
> +}
> +
> +##############################################################################
> +
> +cleanup()
> +{
> +       phc_ctl $DEV freq 0.0 &> /dev/null
> +       phc_ctl $DEV set &> /dev/null
> +}
> +
> +settime()
> +{
> +       RET=0
> +
> +       settime_do
> +       check_err $?
> +       log_test "settime"
> +       cleanup
> +}
> +
> +adjtime()
> +{
> +       RET=0
> +
> +       adjtime_do
> +       check_err $?
> +       log_test "adjtime"
> +       cleanup
> +}
> +
> +adjfreq()
> +{
> +       RET=0
> +
> +       adjfreq_do
> +       check_err $?
> +       log_test "adjfreq"
> +       cleanup
> +}
> +
> +trap cleanup EXIT
> +
> +tests_run
> +
> +exit $EXIT_STATUS
> --
> 2.20.1
>

Cool testing framework, thanks!
Some things to consider:
- Why the .5 in the wait commands?
- I suspect there's a huge margin of inaccuracy that the test is
missing by only looking at the 'seconds' portion of the PHC time after
the adjfreq operation (up to 10^9 - 1 ppb, in the worst case).

Tested-by: Vladimir Oltean <olteanv@gmail.com>

Regards,
-Vladimir