Re: [PATCH 21/25] tests/qtest/cmsdk-apb-watchdog-test: Test clock changes

[Philippe Mathieu-Daudé]

On 1/21/21 8:06 PM, Peter Maydell wrote:
> Now that the CMSDK APB watchdog uses its Clock input, it will
> correctly respond when the system clock frequency is changed using
> the RCC register on in the Stellaris board system registers.  Test
> that when the RCC register is written it causes the watchdog timer to
> change speed.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  tests/qtest/cmsdk-apb-watchdog-test.c | 52 +++++++++++++++++++++++++++
>  1 file changed, 52 insertions(+)
...

> +static void test_clock_change(void)
> +{
> +    uint32_t rcc;
> +
> +    /*
> +     * Test that writing to the stellaris board's RCC register to
> +     * change the system clock frequency causes the watchdog
> +     * to change the speed it counts at.
> +     */
> +    g_assert_cmpuint(readl(WDOG_BASE + WDOGRIS), ==, 0);
> +
> +    writel(WDOG_BASE + WDOGCONTROL, 1);
> +    writel(WDOG_BASE + WDOGLOAD, 1000);
> +
> +    /* Step to just past the 500th tick */
> +    clock_step(80 * 500 + 1);

I was wondering about asking you to change that 40000 in patch #3.
Since you use that clearer form here, it would be nice to have it
in #3 too.

Otherwise,
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>