[libcamera-devel] [PATCH] pipeline: raspberrypi: Fix a bug when clearing out Request buffers on stop

[Naushir Patuck]

When RPiCameraData::clearIncompleteRequests() clears out the request queue
during a stop condition, it unconditionally calls completeBuffer() on all
buffers in each request.  This is wrong, as a buffer could have already been
completed as part of the current request, but the request itself may not yet
have completed.

Fix this by checking if the buffers in the request have been completed before
cancelling them.

Fixes: d372aaa10ddb ("pipeline: raspberrypi: Simplify RPiCameraData::clearIncompleteRequests()")
Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 src/libcamera/pipeline/raspberrypi/raspberrypi.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
index f821d8fe1b6c..0bab3bedd402 100644
--- a/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
+++ b/src/libcamera/pipeline/raspberrypi/raspberrypi.cpp
@@ -1520,8 +1520,14 @@ void RPiCameraData::clearIncompleteRequests()
 
 		for (auto &b : request->buffers()) {
 			FrameBuffer *buffer = b.second;
-			buffer->cancel();
-			pipe_->completeBuffer(request, buffer);
+			/*
+			 * Has the buffer already been handed back to the
+			 * request? If not, do so now.
+			 */
+			if (buffer->request()) {
+				buffer->cancel();
+				pipe_->completeBuffer(request, buffer);
+			}
 		}
 
 		pipe_->completeRequest(request);
-- 
2.25.1