HAL_ADC_ConvCpltCallback optimized away

[carlesls2]

Post edited to follow the community rules: Please review how to share a code in this post.

Using the stm32g030k8 and the Version: 1.18.1 STM32CubeIDE

I just recently applied an optimization in order to get more space for my application firmware. And then I realize that the HAL_ADC_ConvCpltCallback has been optimized away. I use the -Og (debug optimization) to use the less agressive and more debug friendly optimization. 

__attribute__((used)) void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc1)
{
ADC_Average_Buff[CHANNEL_VREF] = ADC_DMA_Buff[CHANNEL_VREF];

ADC_Average_Buff[CHANNEL_VBAT] = ADC_DMA_Buff[CHANNEL_VBAT];

ADC_Average_Buff[CHANNEL_CURRENT] = ADC_DMA_Buff[CHANNEL_CURRENT];

ADC_Average_Buff[CHANNEL_TEMPERATURE] = ADC_DMA_Buff[CHANNEL_TEMPERATURE];

ADC_Average_Buff[CHANNEL_VREF] += ADC_DMA_Buff[CHANNEL_VREF];

ADC_Average_Buff[CHANNEL_VBAT] += ADC_DMA_Buff[CHANNEL_VBAT];

ADC_Average_Buff[CHANNEL_CURRENT] += ADC_DMA_Buff[CHANNEL_CURRENT];

ADC_Average_Buff[CHANNEL_TEMPERATURE] += ADC_DMA_Buff[CHANNEL_TEMPERATURE];

//-------------------------------------------------------------

if (ADC_Samples >= ADC_SAMPLES - 1)

{

//------------------------------

// Voltage Reference calculation

if (ADC_Average_Buff[CHANNEL_VREF] > 0)

{

VoltageReference_Dig = (uint16_t) ADC_Average_Buff[CHANNEL_VREF] / ADC_SAMPLES;

VoltageReference = (uint16_t) __LL_ADC_CALC_VREFANALOG_VOLTAGE( VoltageReference_Dig, LL_ADC_RESOLUTION_12B);

}

else

{

VoltageReference = VDDA_APPLI;

// WARNING: Measure error, action: pending.

}

//------------------------------

// Voltage Battery calculation

if (ADC_Average_Buff[CHANNEL_VBAT] > 0)

{

VoltageBattery_Dig = (uint16_t) ADC_Average_Buff[CHANNEL_VBAT]/ ADC_SAMPLES;

VoltageBattery_Pin = (uint16_t) __LL_ADC_CALC_DATA_TO_VOLTAGE( VoltageReference, VoltageBattery_Dig,LL_ADC_RESOLUTION_12B);

ConversionFloat_Auxiliar = (float) (VoltageBattery_Pin);

if (ConversionFloat_Auxiliar > 0)

{

ConversionFloat_Auxiliar = ((((ConversionFloat_Auxiliar / 1000) / ADC_VBAT_R2) * (ADC_VBAT_R2 + ADC_VBAT_R1)) * 1000)+ ADC_VBAT_OFFSET;

//ConversionFloat_Auxiliar /= 1000;

}

else

{

ConversionFloat_Auxiliar = 0;

}

VoltageBattery = (uint16_t)ConversionFloat_Auxiliar;

}

else

{

// WARNING: Measure error, action: pending.

}

//------------------------------

// Current Motor calculation

if (ADC_Average_Buff[CHANNEL_CURRENT] > 0) // index == 1

{

VoltageMotorShunt_Dig = (uint16_t) ADC_Average_Buff[CHANNEL_CURRENT] / ADC_SAMPLES;

VoltageMotorShunt_Pin = (uint16_t) __LL_ADC_CALC_DATA_TO_VOLTAGE( VoltageReference, VoltageMotorShunt_Dig,

LL_ADC_RESOLUTION_12B);

ConversionFloat_Auxiliar = (float) (VoltageMotorShunt_Pin);

if (ConversionFloat_Auxiliar > 0)

{

ConversionFloat_Auxiliar = (((ConversionFloat_Auxiliar / 1000)/ ADC_SHUNT) * 1000) + ADC_MOTOR_SHUNT_OFFSET;

}

else

{

ConversionFloat_Auxiliar = 0;

}

CurrentMotor = ConversionFloat_Auxiliar;

}

else

{

// WARNING: Measure error, action: pending.

}

//------------------------------

// Temperature calculation

if (ADC_Average_Buff[CHANNEL_TEMPERATURE] > 0)

{

Temperature_Dig = (uint16_t) ADC_Average_Buff[CHANNEL_TEMPERATURE] / ADC_SAMPLES;

Temperature = 100*(int16_t) __LL_ADC_CALC_TEMPERATURE(VoltageReference, Temperature_Dig, LL_ADC_RESOLUTION_12B);

}

else

{

// WARNING: Measure error, action: pending.

}

//------------------------------

// Initialization buffers

ADC_Samples = 0;

ADC_Average_Buff[CHANNEL_VREF] = 0;

ADC_Average_Buff[CHANNEL_VBAT] = 0;

ADC_Average_Buff[CHANNEL_CURRENT] = 0;

ADC_Average_Buff[CHANNEL_TEMPERATURE] = 0;

//------------------------------



//------------------------------

}

else

{

ADC_Samples++;

}

} // End HAL_ADC_ConvCpltCallback

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As the reader can see, I have added the __attribute__((used)) but it is still being optimized away. I also check if the ADC_DMAConvCplt or HAL_ADC_IRQHandler or DMA1_Channel1_IRQHandler are being called, but they are not being called.  

what should I do next?

Thanks for all. 

[Ozone]

First, there is a "insert code sample" menu entry, which makes code snippets like yours much more readable.

Second, declare your ADC_Average_Buff array volatile.
It is highly recommended (read: required) for variables changed in interrupt context anyway.

> __attribute__((used)) void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc1)

It would be new to me that "__attribute__((used))" has any effect on functions.

[Saket_Om]

Hello @carlesls2 

Did you try to disable optimization for the callback function? 

#pragma GCC push_options
#pragma GCC optimize ("O0")  // Disable optimization for this function
void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc) {
    // Your callback implementation
}
#pragma GCC pop_options

[carlesls2]

what is push_options and pop_options?

#pragma GCC push_options

#pragma GCC pop_options

 Thank you.

[Saket_Om]

Hello @carlesls2 

Please check the GCC manual. 

[Andrew Neil]

---

@carlesls2 wrote:

the HAL_ADC_ConvCpltCallback has been optimized away.

---

How are you sure that the function has been optimised away?

As @Ozone suggests, if you haven't qualified things which get modified in the callback as volatile, then accesses to those variables may get optimised-out.

---

@carlesls2 wrote:

I also check if the ADC_DMAConvCplt or HAL_ADC_IRQHandler or DMA1_Channel1_IRQHandler are being called, but they are not being called.  

---

Sounds like the hardware interrupts are not happening...

[carlesls2]

I does not seem optimized away... it exists in the .map file. I guess this is not discarted... it seems not optimized away but it is never called. Yet this occurs when the optimization is applied. 

[Ozone]

These callbacks are called from within the interrupt handler - hence their name.
I don't use Cube/HAL code, so you would need to check the respective ADC interrupt handler implementation. But they are supposedly called from there.

Perhaps some conditional code, or some preprocessor conditions (#if <..>) applying.
You could set a debug breakpoint in the handler, and step through.
Only avoid opening a interrupt status register view.

[TDK]

> And then I realize that the HAL_ADC_ConvCpltCallback has been optimized away.

Why do you think it's optimized away? Convince us.

Ensure ADC_Average_Buff is set to volatile.

[carlesls2]

I am not sure but whenever the optimization is applied (when I apply the -Og optimization) the HAL_ADC_ConvCpltCallback is never triggered. The It may not be optimized away but this occurs because of the optimization. 

I created a new smaller project to see if the HAL_ADC_ConvCpltCallback is being optimized away and it is not.