* limits reported by every block in the pipeline.
*
* Return 0 if all formats match, or -EPIPE if at least one link is found with
- * different formats on its two ends.
+ * different formats on its two ends or if the pipeline doesn't start with a
+ * video source (either a subdev with no input pad, or a non-subdev entity).
*/
static int isp_video_validate_pipeline(struct isp_pipeline *pipe)
{
* in the middle of it. */
shifter_link = subdev == &isp->isp_ccdc.subdev;
- /* Retrieve the source format */
+ /* Retrieve the source format. Return an error if no source
+ * entity can be found, and stop checking the pipeline if the
+ * source entity isn't a subdev.
+ */
pad = media_entity_remote_source(pad);
- if (pad == NULL ||
- media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
+ if (pad == NULL)
+ return -EPIPE;
+
+ if (media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
break;
subdev = media_entity_to_v4l2_subdev(pad->entity);
if (video->isp->pdata->set_constraints)
video->isp->pdata->set_constraints(video->isp, false);
media_entity_pipeline_stop(&video->video.entity);
+ /* The DMA queue must be emptied here, otherwise CCDC interrupts
+ * that will get triggered the next time the CCDC is powered up
+ * will try to access buffers that might have been freed but
+ * still present in the DMA queue. This can easily get triggered
+ * if the above omap3isp_pipeline_set_stream() call fails on a
+ * system with a free-running sensor.
+ */
+ INIT_LIST_HEAD(&video->dmaqueue);
video->queue = NULL;
}