I've already contacted support, so this post is just for community.
There's a bug in HAL_SetTickFreq function (stm32f4xx_hal.c)
---8<---
HAL_StatusTypeDef HAL_SetTickFreq(HAL_TickFreqTypeDef Freq)
{
HAL_StatusTypeDef status = HAL_OK;
assert_param(IS_TICKFREQ(Freq));
if (uwTickFreq != Freq)
{
uwTickFreq = Freq;
/* Apply the new tick Freq */
status = HAL_InitTick(uwTickPrio);
}
return status;
}
--->8---
If HAL_InitTick fails, the frequency remains unchanged whereas uwTickFreq is changed. E.g. I have stm32f407vgt6 working on 168MHz with 1kHz SysTick . I want to set SysTick to 10Hz, so I call HAL_SetTickFreq( HAL_TICK_FREQ_10HZ ). Eventually SysTick_Config fails because (16800000 - 1) is bigger than SysTick_LOAD_RELOAD_Msk (0xFFFFFFUL). But uwTickFreq is already == HAL_TICK_FREQ_10HZ, so the ticks are now counted incorrectly. HAL_SetTickFreq function should be changed to something like this:
---8
...
if (uwTickFreq != Freq)
{
/* Apply the new tick Freq */
status = HAL_InitTick(uwTickPrio);
if (HAL_OK == status) {
uwTickFreq = Freq;
}
}
...
--->8---
