ADC3 Multichannel Scan Mode using DMA not working.

[sbstek]

I tried doing line by line debugging to find out that Error code is being set by:

HAL_StatusTypeDef HAL_DMA_Start_IT(DMA_HandleTypeDef *hdma, uint32_t SrcAddress, uint32_t DstAddress, uint32_t DataLength)

To be specific, this line of the code:

else
 
 {
 
 /* Process unlocked */
 
 __HAL_UNLOCK(hdma);
 
 
 /* Set the error code to busy */
 
 hdma->ErrorCode = HAL_DMA_ERROR_BUSY; // the error code is set here.
 
 
 /* Return error status */
 
 status = HAL_ERROR;
 
 }
 
 return status;
 
}

here is my ADC config:

hadc3.Instance = ADC3;
 
 if (HAL_ADC_DeInit(&hadc3) != HAL_OK)
 { Error_Handler(); }
 
 hadc3.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV2; /* Asynchronous clock mode, input ADC clock divided by 2*/
 hadc3.Init.Resolution = ADC_RESOLUTION_12B; /* 16-bit resolution for converted data */
 hadc3.Init.ScanConvMode = ADC_SCAN_ENABLE; /* Sequencer disabled (ADC conversion on only 1 channel: channel set on rank 1) */
 hadc3.Init.EOCSelection = ADC_EOC_SINGLE_CONV; /* EOC flag picked-up to indicate conversion end */
 hadc3.Init.LowPowerAutoWait = DISABLE; /* Auto-delayed conversion feature disabled */
 hadc3.Init.ContinuousConvMode = ENABLE; /* Continuous mode enabled */
 hadc3.Init.NbrOfConversion = 3; 
 hadc3.Init.DiscontinuousConvMode = DISABLE; /* Parameter discarded because sequencer is disabled */
 hadc3.Init.ExternalTrigConv = ADC_SOFTWARE_START; /* Software start to trig the 1st conversion manually, without external event */
 hadc3.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE; /* software trigger chosen */
 hadc3.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DMA_CIRCULAR; /* ADC DMA circular */
 hadc3.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN; /* DR register is overwritten*/
 hadc3.Init.OversamplingMode = DISABLE; /* No oversampling */
 /* Initialize ADC peripheral according to the passed parameters */
 
 if (HAL_ADC_Init(&hadc3) != HAL_OK)
 { Error_Handler(); }
 /* ### - 2 - Start calibration ############################################ */
 if (HAL_ADCEx_Calibration_Start(&hadc3, ADC_CALIB_OFFSET, ADC_SINGLE_ENDED) != HAL_OK)
 { Error_Handler(); }
 
 

DMA config for ADC 3 is as follows:

__HAL_RCC_GPIOF_CLK_ENABLE();
	 /* ADC Periph clock enable */
	 __HAL_RCC_ADC3_CLK_ENABLE();
	 /* ADC Periph interface clock configuration */
	 /* Enable DMA clock */
	 __HAL_RCC_DMA2_CLK_ENABLE();
 
	 /*##- 2- Configure peripheral GPIO #########################################*/
	 GPIO_InitStruct.Pin = GPIO_PIN_6 | GPIO_PIN_4 | GPIO_PIN_5;
	 GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
	 GPIO_InitStruct.Pull = GPIO_NOPULL;
	 HAL_GPIO_Init(GPIOF, &GPIO_InitStruct);
 
	 hdma_adc3.Instance = DMA1_Stream2;
	 hdma_adc3.Init.Request = DMA_REQUEST_ADC3;
	 hdma_adc3.Init.Direction = DMA_PERIPH_TO_MEMORY;
	 hdma_adc3.Init.PeriphInc = DMA_PINC_DISABLE;
	 hdma_adc3.Init.MemInc = DMA_MINC_ENABLE;
	 hdma_adc3.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
	 hdma_adc3.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
	 hdma_adc3.Init.Mode = DMA_CIRCULAR;
	 hdma_adc3.Init.Priority = DMA_PRIORITY_HIGH;
	 hdma_adc3.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
 
	 __HAL_LINKDMA(hadc,DMA_Handle,hdma_adc3);
	 HAL_NVIC_SetPriority(DMA1_Stream2_IRQn, 0, 1);
	 HAL_NVIC_EnableIRQ(DMA1_Stream2_IRQn);

I have tried looking into other posts about the same issue where one of the issue with D cache enabled was that DMA cant access DTCM section of RAM. But i can confirm i am using RAM from section AXI-RAM starting from 0x24000000.

I have also tried using FIFO mode as suggested by another post but still the error code was set by the HAL_DMA_START_IT(..) function.