HAL_HRTIM_WaveformCounterStop_IT delay due to "delai"

[KTyte.1]

Hi. Im using HRTIM and HAL in my project.
To stop Master timer with subsequent interrupt call I use HAL_HRTIM_WaveformCounterStop_IT (it is defined in stm32_hal_legacy.h) and it calls HAL_HRTIM_WaveformCountStop_IT from stm32g4xx_hal_hrtim.c.
Pic.1 shows how long it takes to process this function call, and it is enormous 27.94us.
Yes, I know HAL is kinda slow and for maximum efficiency one should use direct registers call.
I suggest the culprit is delay inserted in this function (variable called "delai").

HAL_StatusTypeDef HAL_HRTIM_WaveformCountStop_IT(HRTIM_HandleTypeDef *hhrtim,
                                                 uint32_t Timers)
{
  /* ++ WA */
  __IO uint32_t delai = (uint32_t)(0x17FU);
  /* -- WA */

  uint8_t timer_idx;

  /* Check the parameters */
  assert_param(IS_HRTIM_TIMERID(Timers));

  /* Process Locked */
  __HAL_LOCK(hhrtim);

  hhrtim->State = HAL_HRTIM_STATE_BUSY;

  /* Disable HRTIM interrupts (if required) */
  __HAL_HRTIM_DISABLE_IT(hhrtim, hhrtim->Init.HRTIMInterruptRequests);

  /* Disable master timer related interrupts (if required) */
  if ((Timers & HRTIM_TIMERID_MASTER) != 0U)
  {
    /* Interrupts enable flag must be cleared one by one */
    __HAL_HRTIM_MASTER_DISABLE_IT(hhrtim, hhrtim->TimerParam[HRTIM_TIMERINDEX_MASTER].InterruptRequests);
  }

  /* Disable timing unit related interrupts (if required) */
  for (timer_idx = HRTIM_TIMERINDEX_TIMER_A ;
       timer_idx < HRTIM_TIMERINDEX_MASTER ;
       timer_idx++)
  {
    if ((Timers & TimerIdxToTimerId[timer_idx]) != 0U)
    {
      __HAL_HRTIM_TIMER_DISABLE_IT(hhrtim, timer_idx, hhrtim->TimerParam[timer_idx].InterruptRequests);
    }
  }

  /* ++ WA */
  do { delai--; } while (delai != 0U);
  /* -- WA */

  /* Disable timer(s) counter */
  hhrtim->Instance->sMasterRegs.MCR &= ~(Timers);

  hhrtim->State = HAL_HRTIM_STATE_READY;

  /* Process Unlocked */
  __HAL_UNLOCK(hhrtim);

  return HAL_OK;
}

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 When I commented line 40 

 /* ++ WA */
// do { delai--; } while (delai != 0U);
 /* -- WA */

execution time drastically decreased to 3.18us (Pic. 2).

So the question is:

What is the purpose of this delay?

Can I just comment it?

What is "WA" mean in the comments near delai? (workaround?).

I did not find any mentions about it in errata, and I checked that this delay was there since version 1.0.0 of STM32Cube MCU package.Pic.1 HAL_HRTIM_WaveformCountStop_IT call execution time.Pic.2 HAL_HRTIM_WaveformCountStop_IT call execution time with commented delai cycle..

[Andrew Neil]

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@KTyte.1 wrote:

What is "WA" means in comments near delai? (workaround?). 

---

It looks like a marker to identify all modifications associated with a Patch - could also be the author's initials.

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@KTyte.1 wrote:

I checked that this delay was there since version 1.0.0 of STM32Cube MCU package.

---

You mean STM32CubeG4 ?

Probably means it was inherited from whatever that package was based on...

[KTyte.1]

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@Andrew Neil wrote:

---

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You mean STM32CubeG4 ?

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Yes, I meant STM32CubeG4 package.

[Andrew Neil]

It's also in CubeF3:

https://github.com/STMicroelectronics/stm32f3xx-hal-driver/blob/master/Src/stm32f3xx_hal_hrtim.c

[KTyte.1]

And in CubeH7:
https://github.com/STMicroelectronics/stm32h7xx-hal-driver/blob/66e5110cb6c7f7d997303db329de83edc2800dae/Src/stm32h7xx_hal_hrtim.c#L5267C2-L5267C44