[v6,3/3] libcamera: software_isp: Clean up pending requests on stop
diff mbox series

Message ID 20241106201721.1624461-4-mzamazal@redhat.com
State Accepted
Commit 2cbf863f3f38f22e5e81dd35a77f1cee84f74d0a
Headers show
Series
  • Clean up pending requests on stop in software ISP
Related show

Commit Message

Milan Zamazal Nov. 6, 2024, 8:17 p.m. UTC 
PipelineHandler::stop() calls stopDevice() method to perform pipeline
specific cleanup and then completes waiting requests.  If any queued
requests remain, an assertion error is raised.

Software ISP stores request buffers in
SimpleCameraData::conversionQueue_ and queues them as V4L2 signals
bufferReady.  stopDevice() cleanup forgets to clean up the buffers and
their requests from conversionQueue_, possibly resulting in the
assertion error.  This patch fixes the omission.

The problem wasn't very visible when
SimplePipelineHandler::kNumInternalBuffers (the number of buffers
allocated in V4L2) was equal to the number of buffers exported from
software ISP.  But when the number of the exported buffers was increased
by one in commit abe2ec64f9e4e97bbdfe3a50372611bd7b5315c2, the assertion
error started pop up in some environments.  Increasing the number of the
buffers much more, e.g. to 9, makes the problem very reproducible.

Each pipeline uses its own mechanism to track the requests to clean up
and it can't be excluded that similar omissions are present in other
places.  But there is no obvious way to make a common cleanup for all
the pipelines (except for doing it instead of raising the assertion
error, which is probably undesirable, in order not to hide incomplete
pipeline specific cleanups).

Bug: https://bugs.libcamera.org/show_bug.cgi?id=234
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Tested-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
---
 src/libcamera/pipeline/simple/simple.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

Patch
diff mbox series 

diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index 13c0a1891..b425bc0de 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -226,6 +226,7 @@  public:
 			 V4L2Subdevice::Whence whence,
 			 Transform transform = Transform::Identity);
 	void bufferReady(FrameBuffer *buffer);
+	void clearIncompleteRequests();
 
 	unsigned int streamIndex(const Stream *stream) const
 	{
@@ -876,6 +877,14 @@  void SimpleCameraData::bufferReady(FrameBuffer *buffer)
 	pipe->completeRequest(request);
 }
 
+void SimpleCameraData::clearIncompleteRequests()
+{
+	while (!conversionQueue_.empty()) {
+		pipe()->cancelRequest(conversionQueue_.front().request);
+		conversionQueue_.pop();
+	}
+}
+
 void SimpleCameraData::conversionInputDone(FrameBuffer *buffer)
 {
 	/* Queue the input buffer back for capture. */
@@ -1401,6 +1410,7 @@  void SimplePipelineHandler::stopDevice(Camera *camera)
 
 	video->bufferReady.disconnect(data, &SimpleCameraData::bufferReady);
 
+	data->clearIncompleteRequests();
 	data->conversionBuffers_.clear();
 
 	releasePipeline(data);