stm32 HAL CAN receive massage in normal mode, it receives but does not come out of interrupt - stm32

Question

I wrote a simple code as below for receiving data via can bus.
I have a board and a can bus analyzer for testing. I send data from analyzer to the board.
in debug mode I saw that the data is received correctly, the "data_received" variable is set to '1' too, but the "b" variable has not changed.
it seems that we dont come out of the interrupt function and dont come to while(1)
#include "main.h"
CAN_HandleTypeDef hcan1;
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_CAN1_Init(void);
CAN_RxHeaderTypeDef RxHeader;
uint8_t data[2];
volatile int data_received=0;
volatile int b=0;
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
if(hcan->Instance==CAN1)
{
HAL_CAN_GetRxMessage(hcan,CAN_RX_FIFO0,&RxHeader,data);
}
if (RxHeader.DLC==2)
{
data_received=1;
}
else
{
data_received=0;
}
}
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_CAN1_Init();
if (HAL_CAN_Start(&hcan1) != HAL_OK)
{
Error_Handler();
}
if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING)!= HAL_OK)
{
Error_Handler();
}
while (1)
{
if (data_received==1)
{
b=1;
data_received=0;
}
}
}
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 25;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 4;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
{
Error_Handler();
}
}
static void MX_CAN1_Init(void)
{
hcan1.Instance = CAN1;
hcan1.Init.Prescaler = 3;
hcan1.Init.Mode = CAN_MODE_NORMAL;
hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_11TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_2TQ;
hcan1.Init.TimeTriggeredMode = DISABLE;
hcan1.Init.AutoBusOff = DISABLE;
hcan1.Init.AutoWakeUp = DISABLE;
hcan1.Init.AutoRetransmission = DISABLE;
hcan1.Init.ReceiveFifoLocked = DISABLE;
hcan1.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan1) != HAL_OK)
{
Error_Handler();
}
CAN_FilterTypeDef canfilterconfig;
canfilterconfig.FilterActivation = CAN_FILTER_ENABLE;
canfilterconfig.FilterBank = 18;
canfilterconfig.FilterFIFOAssignment = CAN_RX_FIFO0;
canfilterconfig.FilterIdHigh = 0x103<<5;
canfilterconfig.FilterIdLow = 0x0000;
canfilterconfig.FilterMaskIdHigh = 0x103<<5;
canfilterconfig.FilterMaskIdLow = 0x0000;
canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;
canfilterconfig.SlaveStartFilterBank = 20;
HAL_CAN_ConfigFilter(&hcan1, &canfilterconfig);
}
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
/* GPIO Ports Clock Enable */
__HAL_RCC_GPIOH_CLK_ENABLE();
__HAL_RCC_GPIOE_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
HAL_GPIO_WritePin(GPIOE, GPIO_PIN_11, GPIO_PIN_SET);
GPIO_InitStruct.Pin = GPIO_PIN_11;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
}
void Error_Handler(void)
{
__disable_irq();
while (1)
{
}
}
#ifdef USE_FULL_ASSERT
void assert_failed(uint8_t *file, uint32_t line)
{
}
#endif

Answer 1

Have a look inside HAL_CAN_GetRxMessage function, all eight data array bytes are always initialized:
aData[0] = (uint8_t)((CAN_RDL0R_DATA0 & hcan->Instance->sFIFOMailBox[RxFifo].RDLR) >> CAN_RDL0R_DATA0_Pos);
aData[1] = (uint8_t)((CAN_RDL0R_DATA1 & hcan->Instance->sFIFOMailBox[RxFifo].RDLR) >> CAN_RDL0R_DATA1_Pos);
aData[2] = (uint8_t)((CAN_RDL0R_DATA2 & hcan->Instance->sFIFOMailBox[RxFifo].RDLR) >> CAN_RDL0R_DATA2_Pos);
aData[3] = (uint8_t)((CAN_RDL0R_DATA3 & hcan->Instance->sFIFOMailBox[RxFifo].RDLR) >> CAN_RDL0R_DATA3_Pos);
aData[4] = (uint8_t)((CAN_RDH0R_DATA4 & hcan->Instance->sFIFOMailBox[RxFifo].RDHR) >> CAN_RDH0R_DATA4_Pos);
aData[5] = (uint8_t)((CAN_RDH0R_DATA5 & hcan->Instance->sFIFOMailBox[RxFifo].RDHR) >> CAN_RDH0R_DATA5_Pos);
aData[6] = (uint8_t)((CAN_RDH0R_DATA6 & hcan->Instance->sFIFOMailBox[RxFifo].RDHR) >> CAN_RDH0R_DATA6_Pos);
aData[7] = (uint8_t)((CAN_RDH0R_DATA7 & hcan->Instance->sFIFOMailBox[RxFifo].RDHR) >> CAN_RDH0R_DATA7_Pos);
Yet your data array is only two bytes long. HAL_CAN_GetRxMessage overrites other variables. This might not be your problem, but it's an obvious bug that will bite you eventually.
Note, that after compilation, order of the variables might not be the same as in the source. You might think that data_received is getting overriten, but it might not. To find out actual order of the variables you can look at the map file.