StackRduino
diff --git a/‎stmhal/spi.c‎
Lines changed: 3 additions & 1 deletion b/‎stmhal/spi.c‎
Lines changed: 3 additions & 1 deletion
@@ -290,12 +290,14 @@ void spi_deinit(SPI_HandleTypeDef *spi) {
 }
 
 STATIC HAL_StatusTypeDef spi_wait_dma_finished(SPI_HandleTypeDef *spi, uint32_t timeout) {
+    // Note: we can't use WFI to idle in this loop because the DMA completion
+    // interrupt may occur before the WFI.  Hence we miss it and have to wait
+    // until the next sys-tick (up to 1ms).
     uint32_t start = HAL_GetTick();
     while (HAL_SPI_GetState(spi) != HAL_SPI_STATE_READY) {
         if (HAL_GetTick() - start >= timeout) {
             return HAL_TIMEOUT;
         }
-        __WFI();
     }
     return HAL_OK;
 }
Original file line number	Diff line number	Diff line change
`@@ -290,12 +290,14 @@ void spi_deinit(SPI_HandleTypeDef *spi) {`
`290`	`290`	`}`
`291`	`291`
`292`	`292`	`STATIC HAL_StatusTypeDef spi_wait_dma_finished(SPI_HandleTypeDef *spi, uint32_t timeout) {`
	`293`	`+ // Note: we can't use WFI to idle in this loop because the DMA completion`
	`294`	`+ // interrupt may occur before the WFI. Hence we miss it and have to wait`
	`295`	`+ // until the next sys-tick (up to 1ms).`
`293`	`296`	`uint32_t start = HAL_GetTick();`
`294`	`297`	`while (HAL_SPI_GetState(spi) != HAL_SPI_STATE_READY) {`
`295`	`298`	`if (HAL_GetTick() - start >= timeout) {`
`296`	`299`	`return HAL_TIMEOUT;`
`297`	`300`	`}`
`298`		`- __WFI();`
`299`	`301`	`}`
`300`	`302`	`return HAL_OK;`
`301`	`303`	`}`