STM32C071RB Problem with PWM + DMA (only works once)

[EngEmil]

I'm working on a STM32C071RB, which I've managed to generate PWM pulses as desired. However, I try to more than once while the chip is running, it stops working.

My main.c file:

#include "main.h"

#define PWM_HI (12)
#define PWM_LO (6)


TIM_HandleTypeDef htim1;
DMA_HandleTypeDef hdma_tim1_ch1;

uint8_t wr_buf[32] = {0};

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_TIM1_Init(void);

void led_set_RGB(uint8_t r, uint8_t g, uint8_t b) {
	for(int i = 0; i < 8; i++){
		wr_buf[i] = (g & (1 << i)) ? PWM_HI : PWM_LO;
		wr_buf[i + 8] = (r & (1 << i)) ? PWM_HI : PWM_LO;
		wr_buf[i + 16] = (b & (1 << i)) ? PWM_HI : PWM_LO;
	}
}

void led_render() {
	while (HAL_DMA_GetState(&hdma_tim1_ch1) != HAL_DMA_STATE_READY) {}
	HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_1, (uint32_t *)wr_buf, 32);
}

void HAL_TIM_PWM_PulseFinishedCallback(TIM_HandleTypeDef *htim) {
	if (htim->Instance == TIM1) {
		// Stop PWM and DMA after all pulses are transfered
		HAL_TIM_PWM_Stop_DMA(htim, TIM_CHANNEL_1);
    }
}

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_TIM1_Init();
  
  while (1)
  {
	  led_set_RGB(0xFF,0x00,0x00);
	  led_render();
	  HAL_Delay(500);

	  led_set_RGB(0x00,0xFF,0x00);
	  led_render();
	  HAL_Delay(500);

	  led_set_RGB(0x00,0x00,0xFF);
	  led_render();
	  HAL_Delay(500);

  }

}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  __HAL_FLASH_SET_LATENCY(FLASH_LATENCY_1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSIDiv = RCC_HSI_DIV1;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.SYSCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_APB1_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_TIM1_Init(void)
{
  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};
  TIM_BreakDeadTimeConfigTypeDef sBreakDeadTimeConfig = {0};

  htim1.Instance = TIM1;
  htim1.Init.Prescaler = 2;
  htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim1.Init.Period = 19;
  htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim1.Init.RepetitionCounter = 0;
  htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
  {
    Error_Handler();
  }
  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterOutputTrigger2 = TIM_TRGO2_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 0;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCNPolarity = TIM_OCNPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  sConfigOC.OCIdleState = TIM_OCIDLESTATE_RESET;
  sConfigOC.OCNIdleState = TIM_OCNIDLESTATE_RESET;
  if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
  {
    Error_Handler();
  }
  sBreakDeadTimeConfig.OffStateRunMode = TIM_OSSR_DISABLE;
  sBreakDeadTimeConfig.OffStateIDLEMode = TIM_OSSI_DISABLE;
  sBreakDeadTimeConfig.LockLevel = TIM_LOCKLEVEL_OFF;
  sBreakDeadTimeConfig.DeadTime = 0;
  sBreakDeadTimeConfig.BreakState = TIM_BREAK_DISABLE;
  sBreakDeadTimeConfig.BreakPolarity = TIM_BREAKPOLARITY_HIGH;
  sBreakDeadTimeConfig.BreakFilter = 0;
  sBreakDeadTimeConfig.BreakAFMode = TIM_BREAK_AFMODE_INPUT;
  sBreakDeadTimeConfig.Break2State = TIM_BREAK2_DISABLE;
  sBreakDeadTimeConfig.Break2Polarity = TIM_BREAK2POLARITY_HIGH;
  sBreakDeadTimeConfig.Break2Filter = 0;
  sBreakDeadTimeConfig.Break2AFMode = TIM_BREAK_AFMODE_INPUT;
  sBreakDeadTimeConfig.AutomaticOutput = TIM_AUTOMATICOUTPUT_DISABLE;
  if (HAL_TIMEx_ConfigBreakDeadTime(&htim1, &sBreakDeadTimeConfig) != HAL_OK)
  {
    Error_Handler();
  }

  HAL_TIM_MspPostInit(&htim1);

}

static void MX_DMA_Init(void)
{
  __HAL_RCC_DMA1_CLK_ENABLE();

  HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);

}

static void MX_GPIO_Init(void)
{

  __HAL_RCC_GPIOA_CLK_ENABLE();

}

void Error_Handler(void)
{

  __disable_irq();
  while (1)
  {
  }
}
#ifdef USE_FULL_ASSERT

void assert_failed(uint8_t *file, uint32_t line)
{

}
#endif /* USE_FULL_ASSERT */

 
As you can see in the while loop in the main function, it manages to run the first segment of led_render(), however, whenever led_render() is called again, it just leads to HAL_TIM_PWM_Start_DMA() to return HAL_ERROR, which seem to be coming from HAL_DMA_Start_IT().

Update:

I discovered, by not calling HAL_TIM_PWM_Stop_DMA(), it works fine. Might be a bug that you cannot call the _Start_DMA() after _Stop_DMA() ??