video: stm32_dcmi: DMA Error recovery

On several boards, such as the Arduino Giga and
Portenta H7, they are often times setup with their
camera buffers and potentially video buffers in
SDRam.  This can lead to a significant number of
DMA errors, which currently stops the camera from
returning any additional frames.

Signed-off-by: Kurt Eckhardt <[email protected]>

Author: KurtE

drivers/video/video_stm32_dcmi.c

@@ -55,9 +55,31 @@ struct video_stm32_dcmi_config {
 	const struct stream dma;
 };
 
+static void stm32_dcmi_process_dma_error(DCMI_HandleTypeDef *hdcmi)
+{
+	struct video_stm32_dcmi_data *dev_data =
+		CONTAINER_OF(hdcmi, struct video_stm32_dcmi_data, hdcmi);
+
+	LOG_DBG("Restart DMA after Error!");
+
+	/* Lets try to recover by stopping and restart */
+	if (HAL_DCMI_Stop(&dev_data->hdcmi) != HAL_OK) {
+		LOG_WRN("HAL_DCMI_Stop FAILED!");
+		return;
+	}
+
+	if (HAL_DCMI_Start_DMA(&dev_data->hdcmi,
+			       DCMI_MODE_CONTINUOUS,
+			       (uint32_t)dev_data->vbuf->buffer,
+			       dev_data->vbuf->size / 4) != HAL_OK) {
+		LOG_WRN("Continuous: HAL_DCMI_Start_DMA FAILED!");
+		return;
+	}
+}
+
 void HAL_DCMI_ErrorCallback(DCMI_HandleTypeDef *hdcmi)
 {
-	LOG_WRN("%s", __func__);
+	stm32_dcmi_process_dma_error(hdcmi);
 }
 
 void HAL_DCMI_FrameEventCallback(DCMI_HandleTypeDef *hdcmi)
@@ -96,19 +118,12 @@ static void dcmi_dma_callback(const struct device *dev, void *arg, uint32_t chan
 	DMA_HandleTypeDef *hdma = arg;
 
 	ARG_UNUSED(dev);
-
-	if (status < 0) {
-		LOG_ERR("DMA callback error with channel %d.", channel);
-	}
+	ARG_UNUSED(channel);
+	ARG_UNUSED(status);
 
 	HAL_DMA_IRQHandler(hdma);
 }
 
-void HAL_DMA_ErrorCallback(DMA_HandleTypeDef *hdma)
-{
-	LOG_WRN("%s", __func__);
-}
-
 static int stm32_dma_init(const struct device *dev)
 {
 	struct video_stm32_dcmi_data *data = dev->data;