[U-Boot] [PATCH 1/2] test: Add a simple time test

[Simon Glass]

+Masahiro


On 2 May 2015 at 09:25, Simon Glass <sjg at chromium.org> wrote:
> Sometimes the time functions are incorrect due to bad time support on a
> board. Add a unit test which tries to detect this.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  test/Kconfig   |   8 ++++
>  test/Makefile  |   1 +
>  test/time_ut.c | 137 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 146 insertions(+)
>  create mode 100644 test/time_ut.c
>
> diff --git a/test/Kconfig b/test/Kconfig
> index 1fb1716..3270c84 100644
> --- a/test/Kconfig
> +++ b/test/Kconfig
> @@ -1 +1,9 @@
> +config CMD_UT_TIME
> +       bool "Unit tests for time functions"
> +       help
> +         Enables the 'ut_time' command which tests that the time functions
> +         work correctly. The test is fairly simple and will not catch all
> +         problems. But if you are having problems with udelay() and the like,
> +         this is a good place to start.
> +
>  source "test/dm/Kconfig"
> diff --git a/test/Makefile b/test/Makefile
> index 9c95805..08330e0 100644
> --- a/test/Makefile
> +++ b/test/Makefile
> @@ -6,3 +6,4 @@
>
>  obj-$(CONFIG_SANDBOX) += command_ut.o
>  obj-$(CONFIG_SANDBOX) += compression.o
> +obj-$(CONFIG_CMD_UT_TIME) += time_ut.o
> diff --git a/test/time_ut.c b/test/time_ut.c
> new file mode 100644
> index 0000000..6b52245
> --- /dev/null
> +++ b/test/time_ut.c
> @@ -0,0 +1,137 @@
> +/*
> + * Copyright (c) 2015 Google, Inc
> + * Written by Simon Glass <sjg at chromium.org>
> + * SPDX-License-Identifier:    GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +#include <errno.h>
> +
> +static int test_get_timer(void)
> +{
> +       ulong base, start, next, diff;
> +       int iter;
> +
> +       base = get_timer(0);
> +       start = get_timer(0);
> +       for (iter = 0; iter < 10; iter++) {
> +               do {
> +                       next = get_timer(0);
> +               } while (start == next);
> +
> +               if (start + 1 != next) {
> +                       printf("%s: iter=%d, start=%lu, next=%lu, expected a difference of 1\n",
> +                              __func__, iter, start, next);
> +                       return -EINVAL;
> +               }
> +               start++;
> +       }
> +
> +       /*
> +        * Check that get_timer(base) matches our elapsed time, allowing that
> +        * an extra millisecond may have passed.
> +        */
> +       diff = get_timer(base);
> +       if (diff != iter && diff != iter + 1) {
> +               printf("%s: expected get_timer(base) to match elapsed time: diff=%lu, expected=%d\n",
> +                      __func__, diff, iter);
> +                       return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
> +static int test_timer_get_us(void)
> +{
> +       ulong prev, next, min = 1000000;
> +       long delta;
> +       int iter;
> +
> +       /* Find the minimum delta we can measure, in microseconds */
> +       prev = timer_get_us();
> +       for (iter = 0; iter < 100; ) {
> +               next = timer_get_us();
> +               if (next != prev) {
> +                       delta = next - prev;
> +                       if (delta < 0) {
> +                               printf("%s: timer_get_us() went backwards from %lu to %lu\n",
> +                                      __func__, prev, next);
> +                               return -EINVAL;
> +                       } else if (delta != 0) {
> +                               if (delta < min)
> +                                       min = delta;
> +                               prev = next;
> +                               iter++;
> +                       }
> +               }
> +       }
> +
> +       if (min != 1) {
> +               printf("%s: Minimum microsecond delta should be 1 but is %lu\n",
> +                      __func__, min);
> +               return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
> +static int test_time_comparison(void)
> +{
> +       ulong start_us, end_us, delta_us;
> +       long error;
> +       ulong start;
> +
> +       start = get_timer(0);
> +       start_us = timer_get_us();
> +       while (get_timer(start) < 1000)
> +               ;
> +       end_us = timer_get_us();
> +       delta_us = end_us - start_us;
> +       error = delta_us - 1000000;
> +       printf("%s: Microsecond time for 1 second: %lu, error = %ld\n",
> +              __func__, delta_us, error);
> +       if (abs(error) > 1000)
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +
> +static int test_udelay(void)
> +{
> +       long error;
> +       ulong start, delta;
> +       int iter;
> +
> +       start = get_timer(0);
> +       for (iter = 0; iter < 1000; iter++)
> +               udelay(1000);
> +       delta = get_timer(start);
> +       error = delta - 1000;
> +       printf("%s: Delay time for 1000 udelay(1000): %lu ms, error = %ld\n",
> +              __func__, delta, error);
> +       if (abs(error) > 100)
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +
> +static int do_ut_time(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
> +{
> +       int ret = 0;
> +
> +       ret |= test_get_timer();
> +       ret |= test_timer_get_us();
> +       ret |= test_time_comparison();
> +       ret |= test_udelay();
> +
> +       printf("Test %s\n", ret ? "failed" : "passed");
> +
> +       return ret ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
> +}
> +
> +U_BOOT_CMD(
> +       ut_time,        1,      1,      do_ut_time,
> +       "Very basic test of time functions",
> +       ""
> +);
> --
> 2.2.0.rc0.207.ga3a616c
>