Posted on August 13, 2014 at 02:22
I am having some trouble getting the expected behavior out of my interrupts for DMA and USB.
Using the STCubeMX HAL libraries, I have configured the interrupts as follows:
/**
* @brief System NVIC priority group
*/
#define GLOBAL_IRQ_PRI_GROUP NVIC_PRIORITYGROUP_2
/**
* @brief Interrupt Priority Settings
*/
#define SYSTICK_PREEMPT_PRI 0
#define SYSTICK_SUB_PRI 0
#define HOST_READY_IRQ_PREEMPT_PRI 1
#define HOST_READY_IRQ_SUB_PRI 0
#define DEVICE_READY_IRQ_PREEMPT_PRI 1
#define DEVICE_READY_IRQ_SUB_PRI 0
#define HOST_SPI_ACTIVE_IRQ_PREEMPT_PRI 1
#define HOST_SPI_ACTIVE_IRQ_SUB_PRI 0
#define SPI_DMA_CHANNEL_IRQ_PREEMPT_PRI 2
#define SPI_DMA_CHANNEL_IRQ_SUB_PRI 0
#define SPI_IRQ_PREEMPT_PRI 2
#define SPI_IRQ_SUB_PRI 0
#define USB_IRQ_PREEMPT_PRI 4
#define USB_IRQ_SUB_PRI 0
/* USB Peripheral interrupt init*/
/* Sets the priority grouping field */
HAL_NVIC_SetPriorityGrouping(GLOBAL_IRQ_PRI_GROUP);
HAL_NVIC_SetPriority(OTG_HS_EP1_IN_IRQn, USB_IRQ_PREEMPT_PRI, USB_IRQ_SUB_PRI);
HAL_NVIC_EnableIRQ(OTG_HS_EP1_IN_IRQn);
/* Sets the priority grouping field */
HAL_NVIC_SetPriorityGrouping(GLOBAL_IRQ_PRI_GROUP);
HAL_NVIC_SetPriority(OTG_HS_IRQn, USB_IRQ_PREEMPT_PRI, USB_IRQ_SUB_PRI);
HAL_NVIC_EnableIRQ(OTG_HS_IRQn);
/* Sets the priority grouping field */
HAL_NVIC_SetPriorityGrouping(GLOBAL_IRQ_PRI_GROUP);
HAL_NVIC_SetPriority(OTG_HS_EP1_OUT_IRQn, USB_IRQ_PREEMPT_PRI, USB_IRQ_SUB_PRI);
HAL_NVIC_EnableIRQ(OTG_HS_EP1_OUT_IRQn);
/* SPI DMA interrupt init */
/* Sets the priority grouping field */
HAL_NVIC_SetPriorityGrouping(GLOBAL_IRQ_PRI_GROUP);
HAL_NVIC_SetPriority(SPI_DMA_RX_IRQn, SPI_DMA_CHANNEL_IRQ_PREEMPT_PRI, SPI_DMA_CHANNEL_IRQ_SUB_PRI);
HAL_NVIC_EnableIRQ(SPI_DMA_RX_IRQn);
/* Sets the priority grouping field */
HAL_NVIC_SetPriorityGrouping(GLOBAL_IRQ_PRI_GROUP);
HAL_NVIC_SetPriority(SPI_DMA_TX_IRQn, SPI_DMA_CHANNEL_IRQ_PREEMPT_PRI, SPI_DMA_CHANNEL_IRQ_SUB_PRI);
HAL_NVIC_EnableIRQ(SPI_DMA_TX_IRQn);
While in the USB interrupt routine, I perform a series of SPI transfers via DMA requests. Unfortunately, I get stuck waiting for my first transfer to complete. I have confirmed that the transfer did in fact occur (the receiving side picked up the correct data) and if I check the interrupt pending bit for the DMA stream in question I see that it was clear before starting the transfer, and set after the reception by the other side.
My understanding was that the configuration I have above should have the DMA interrupt a higher pre-emption priority than the USB interrupt and that it should begin execution even while I am in the USB interrupt. Am I wrong in this understanding or is there some subtle configuration I have messed up?
#stm32 #dma #stmf4 #isr
