[media] omap3isp: isp: Reset the ISP when the pipeline can't be stopped

When a failure to stop a module in the pipeline is detected, the only
way to recover is to reset the ISP. However, as other users can be using
a different pipeline with other modules, the ISP can't be reset
synchronously with the error detection.

Mark the ISP as needing a reset when a failure to stop a pipeline is
detected, and reset the ISP when the last user releases the last
reference to the ISP.

Modify the omap3isp_pipeline_set_stream() function to record the new ISP
pipeline state only when no error occurs, except when stopping the
pipeline in which case the pipeline is still marked as stopped.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/omap3isp/isp.c

@@ -872,6 +872,9 @@ static int isp_pipeline_disable(struct isp_pipeline *pipe)
 		}
 	}
 
+	if (failure < 0)
+		isp->needs_reset = true;
+
 	return failure;
 }
 
@@ -884,7 +887,8 @@ static int isp_pipeline_disable(struct isp_pipeline *pipe)
  * single-shot or continuous mode.
  *
  * Return 0 if successful, or the return value of the failed video::s_stream
- * operation otherwise.
+ * operation otherwise. The pipeline state is not updated when the operation
+ * fails, except when stopping the pipeline.
  */
 int omap3isp_pipeline_set_stream(struct isp_pipeline *pipe,
 				 enum isp_pipeline_stream_state state)
@@ -895,6 +899,8 @@ int omap3isp_pipeline_set_stream(struct isp_pipeline *pipe,
 		ret = isp_pipeline_disable(pipe);
 	else
 		ret = isp_pipeline_enable(pipe, state);
+
+	if (ret == 0 || state == ISP_PIPELINE_STREAM_STOPPED)
 		pipe->stream_state = state;
 
 	return ret;
@@ -1481,6 +1487,10 @@ void omap3isp_put(struct isp_device *isp)
 	if (--isp->ref_count == 0) {
 		isp_disable_interrupts(isp);
 		isp_save_ctx(isp);
+		if (isp->needs_reset) {
+			isp_reset(isp);
+			isp->needs_reset = false;
+		}
 		isp_disable_clocks(isp);
 	}
 	mutex_unlock(&isp->isp_mutex);

drivers/media/video/omap3isp/isp.h

@@ -262,6 +262,7 @@ struct isp_device {
 	/* ISP Obj */
 	spinlock_t stat_lock;	/* common lock for statistic drivers */
 	struct mutex isp_mutex;	/* For handling ref_count field */
+	bool needs_reset;
 	int has_context;
 	int ref_count;
 	unsigned int autoidle;