[libcamera-devel] [PATCH v4 8/8] android: Implement flush() camera operation

paul.elder at ideasonboard.com paul.elder at ideasonboard.com
Fri Jun 4 11:27:09 CEST 2021


Hi Hiro,

On Fri, Jun 04, 2021 at 05:48:45PM +0900, Hirokazu Honda wrote:
> Hi Paul and Laurent,
> 
> On Wed, Jun 2, 2021 at 1:38 PM <paul.elder at ideasonboard.com> wrote:
> 
>     Hi Jacopo,
> 
>     On Wed, Jun 02, 2021 at 03:58:47AM +0300, Laurent Pinchart wrote:
>     > Hi Jacopo,
>     >
>     > On Mon, May 31, 2021 at 03:59:53AM +0300, Laurent Pinchart wrote:
>     > > On Fri, May 28, 2021 at 10:53:28AM +0300, Laurent Pinchart wrote:
>     > > > On Fri, May 28, 2021 at 12:03:59AM +0200, Jacopo Mondi wrote:
>     > > > > Implement the flush() camera operation in the CameraDevice class
>     > > > > and make it available to the camera framework by implementing the
>     > > > > operation wrapper in camera_ops.cpp.
>     > > > >
>     > > > > Introduce a new camera state State::Flushing to handle concurrent
>     > > > > flush() and process_capture_request() calls.
>     > > > >
>     > > > > As flush() can race with processCaptureRequest() protect it
>     > > > > by introducing a new State::Flushing state that
>     > > > > processCaptureRequest() inspects before queuing the Request to the
>     > > > > Camera. If flush() is in progress while processCaptureRequest() is
>     > > > > called, return the current Request immediately in error state. If
>     > > > > flush() has completed and a new call to processCaptureRequest() is
>     > > > > made just after, start the camera again before queuing the request.
>     > > > >
>     > > > > Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
>     > > > > ---
>     > > > >  src/android/camera_device.cpp | 74
>     ++++++++++++++++++++++++++++++++++-
>     > > > >  src/android/camera_device.h   |  3 ++
>     > > > >  src/android/camera_ops.cpp    |  8 +++-
>     > > > >  3 files changed, 83 insertions(+), 2 deletions(-)
>     > > > >
>     > > > > diff --git a/src/android/camera_device.cpp b/src/android/
>     camera_device.cpp
>     > > > > index a20c3eaa0ff6..6a8d4d4d5f76 100644
>     > > > > --- a/src/android/camera_device.cpp
>     > > > > +++ b/src/android/camera_device.cpp
>     > > > > @@ -797,6 +797,23 @@ void CameraDevice::close()
>     > > > >         camera_->release();
>     > > > >  }
>     > > > > 
>     > > > > +void CameraDevice::flush()
>     > > > > +{
>     > > > > +       {
>     > > > > +               MutexLocker stateLock(stateMutex_);
>     > > > > +               if (state_ != State::Running)
>     > > > > +                       return;
>     > > > > +
>     > > > > +               state_ = State::Flushing;
>     > > > > +       }
>     > > > > +
>     > > > > +       worker_.stop();
>     > > > > +       camera_->stop();
>     > > > > +
>     > > > > +       MutexLocker stateLock(stateMutex_);
>     > > > > +       state_ = State::Stopped;
>     > > > > +}
>     > > > > +
>     > > > >  void CameraDevice::stop()
>     > > > >  {
>     > > > >         MutexLocker stateLock(stateMutex_);
>     > > > > @@ -1894,15 +1911,46 @@ int CameraDevice::processControls
>     (Camera3RequestDescriptor *descriptor)
>     > > > >         return 0;
>     > > > >  }
>     > > > > 
>     > > > > +void CameraDevice::abortRequest(camera3_capture_request_t
>     *request)
>     > > > > +{
>     > > > > +       notifyError(request->frame_number, nullptr,
>     CAMERA3_MSG_ERROR_REQUEST);
>     > > > > +
>     > > > > +       camera3_capture_result_t result = {};
>     > > > > +       result.num_output_buffers = request->num_output_buffers;
>     > > > > +       result.frame_number = request->frame_number;
>     > > > > +       result.partial_result = 0;
>     > > > > +
>     > > > > +       std::vector<camera3_stream_buffer_t> resultBuffers
>     (result.num_output_buffers);
>     > > > > +       for (auto [i, buffer] : utils::enumerate(resultBuffers)) {
>     > > > > +               buffer = request->output_buffers[i];
>     > > > > +               buffer.release_fence = request->output_buffers
>     [i].acquire_fence;
>     > > > > +               buffer.acquire_fence = -1;
>     > > > > +               buffer.status = CAMERA3_BUFFER_STATUS_ERROR;
>     > > > > +       }
>     > > > > +       result.output_buffers = resultBuffers.data();
>     > > > > +
>     > > > > +       callbacks_->process_capture_result(callbacks_, &result);
>     > > > > +}
>     > > > > +
>     > > > >  int CameraDevice::processCaptureRequest(camera3_capture_request_t
>     *camera3Request)
>     > > > >  {
>     > > > >         if (!isValidRequest(camera3Request))
>     > > > >                 return -EINVAL;
>     > > > > 
>     > > > >         {
>     > > > > +               /*
>     > > > > +                * Start the camera if that's the first request we
>     handle after
>     > > > > +                * a configuration or after a flush.
>     > > > > +                *
>     > > > > +                * If flush is in progress, return the pending
>     request
>     > > > > +                * immediately in error state.
>     > > > > +                */
>     > > > >                 MutexLocker stateLock(stateMutex_);
>     > > > > +               if (state_ == State::Flushing) {
>     > > > > +                       abortRequest(camera3Request);
>     > > > > +                       return 0;
>     > > > > +               }
>     > > > > 
>     > > > > -               /* Start the camera if that's the first request we
>     handle. */
>     > > > >                 if (state_ == State::Stopped) {
>     > > > >                         worker_.start();
>     > > > > 
>     > > > > @@ -2004,6 +2052,30 @@ int CameraDevice::processCaptureRequest
>     (camera3_capture_request_t *camera3Reques
>     > > > >         if (ret)
>     > > > >                 return ret;
>     > > > > 
>     > > > > +       /*
>     > > > > +        * Just before queuing the request, make sure flush() has
>     not
>     > > > > +        * been called while this function was running. If flush is
>     in progress
>     > > > > +        * abort the request. If flush has completed and has
>     stopped the camera
>     > > > > +        * we have to re-start it to be able to process the
>     request.
>     > > > > +        */
>     > > > > +       MutexLocker stateLock(stateMutex_);
>     > > > > +       if (state_ == State::Flushing) {
>     > > > > +               abortRequest(camera3Request);
>     > > > > +               return 0;
>     > > > > +       }
>     > > >
>     > > > It seems possibly overkill to do this check twice, but it shouldn't
>     > > > hurt. I suspect we'll rework this code later, possibly by adding a
>     > > > Camera::flush() in the libcamera native API, although I'm not
>     entirely
>     > > > sure what benefit it would bring compared to a stop/start. For now
>     this
>     > > > should be fine.
>     > > >
>     > > > > +
>     > > > > +       if (state_ == State::Stopped) {
>     > > > > +               worker_.start();
>     > > > > +
>     > > > > +               ret = camera_->start();
>     > > > > +               if (ret) {
>     > > > > +                       LOG(HAL, Error) << "Failed to start
>     camera";
>     > > > > +                       return ret;
>     > > > > +               }
>     > > > > +
>     > > > > +               state_ = State::Running;
>     > > > > +       }
>     > > >
>     > > > This, however, bothers me a bit. Why do we need to start the camera
>     in
>     > > > two different locations ? Could we drop the first start above ? And
>     if
>     > > > we do so, given that preparing the request should be a short
>     operation,
>     > > > I wonder if we shouldn't also drop the first Flushing check at the
>     top
>     > > > of this function.
>     > >
>     > > This shouldn't be a blocker though, so I'll merge the series after
>     > > running tests. We can address the issue on top.
>     >
>     > I'm afraid this series causes CTS regressions :-(
>     >
>     > I'm running the full camera tests with
>     >
>     > run cts-dev --skip-preconditions -a x86_64 -m CtsCameraTestCases
>     >
>     > With the current master branch, I get 22 or 23 failures (some are a bit
>     > random), and with this series, it increases to 25. Here's the diff:
>     >
>     > @@ -3,14 +3,16 @@
>     >  android.hardware.camera2.cts.ImageReaderTest#testRawPrivate
>     >  android.hardware.camera2.cts.ImageReaderTest#testRepeatingRawPrivate
>     >  android.hardware.camera2.cts.RecordingTest#testSupportedVideoSizes
>     > -android.hardware.camera2.cts.RecordingTest#testVideoSnapshot
>     >  android.hardware.camera2.cts.RobustnessTest#
>     testMandatoryOutputCombinations
>     > +android.hardware.camera2.cts.StillCaptureTest#testFocalLengths
>     > +android.hardware.camera2.cts.StillCaptureTest#testJpegExif
>     >  android.hardware.camera2.cts.StillCaptureTest#
>     testStillPreviewCombination
>     >  android.hardware.camera2.cts.SurfaceViewPreviewTest#testDeferredSurfaces
>     >  android.hardware.cts.CameraGLTest#testSetPreviewTextureBothCallbacks
>     >  android.hardware.cts.CameraGLTest#testSetPreviewTexturePreviewCallback
>     >  android.hardware.cts.CameraTest#testFocusDistances
>     >  android.hardware.cts.CameraTest#testImmediateZoom
>     > +android.hardware.cts.CameraTest#testJpegExif
>     >  android.hardware.cts.CameraTest#testPreviewCallback
>     >  android.hardware.cts.CameraTest#testPreviewCallbackWithBuffer
>     >  android.hardware.cts.CameraTest#testPreviewCallbackWithPicture
> 
>     With the subplan, all of the existing ones are excluded. The
>     RecordingTests are failing at random (I'll file a bug report for this).
> 
>     I've managed to reproduce the three extra failures though, and they
>     consistently fail with a segfault.
> 
> 
> 
> I ran android.hardware.camera2.cts.StillCaptureTest and the failure tests pass.
> Could you tell me on top of what commit you applied the patch series?

On... master. I think 59de56f4 "qcam: Add libatomic dependency".


Paul

>  
> 
> 
>     >
>     > There's some randomness in the RecordingTest, so that may not be
>     > significant. The other three tests seem to pass consistently in master,
>     > and fail consistently with the series applied. They also fail when run
>     > in isolation.
>     >
>     > > > The rest of the patch looks good to me.
>     > > >
>     > > > > +
>     > > > >         worker_.queueRequest(descriptor.request_.get());
>     > > > > 
>     > > > >         {
>     > > > > diff --git a/src/android/camera_device.h b/src/android/
>     camera_device.h
>     > > > > index c949fa509ca4..4aadb27c562c 100644
>     > > > > --- a/src/android/camera_device.h
>     > > > > +++ b/src/android/camera_device.h
>     > > > > @@ -43,6 +43,7 @@ public:
>     > > > > 
>     > > > >         int open(const hw_module_t *hardwareModule);
>     > > > >         void close();
>     > > > > +       void flush();
>     > > > > 
>     > > > >         unsigned int id() const { return id_; }
>     > > > >         camera3_device_t *camera3Device() { return &camera3Device_;
>     }
>     > > > > @@ -92,6 +93,7 @@ private:
>     > > > > 
>     > > > >         enum class State {
>     > > > >                 Stopped,
>     > > > > +               Flushing,
>     > > > >                 Running,
>     > > > >         };
>     > > > > 
>     > > > > @@ -106,6 +108,7 @@ private:
>     > > > >         getRawResolutions(const libcamera::PixelFormat &
>     pixelFormat);
>     > > > > 
>     > > > >         libcamera::FrameBuffer *createFrameBuffer(const
>     buffer_handle_t camera3buffer);
>     > > > > +       void abortRequest(camera3_capture_request_t *request);
>     > > > >         void notifyShutter(uint32_t frameNumber, uint64_t
>     timestamp);
>     > > > >         void notifyError(uint32_t frameNumber, camera3_stream_t
>     *stream,
>     > > > >                          camera3_error_msg_code code);
>     > > > > diff --git a/src/android/camera_ops.cpp b/src/android/
>     camera_ops.cpp
>     > > > > index 696e80436821..8a3cfa175ff5 100644
>     > > > > --- a/src/android/camera_ops.cpp
>     > > > > +++ b/src/android/camera_ops.cpp
>     > > > > @@ -66,8 +66,14 @@ static void hal_dev_dump([[maybe_unused]] const
>     struct camera3_device *dev,
>     > > > >  {
>     > > > >  }
>     > > > > 
>     > > > > -static int hal_dev_flush([[maybe_unused]] const struct
>     camera3_device *dev)
>     > > > > +static int hal_dev_flush(const struct camera3_device *dev)
>     > > > >  {
>     > > > > +       if (!dev)
>     > > > > +               return -EINVAL;
>     > > > > +
>     > > > > +       CameraDevice *camera = reinterpret_cast<CameraDevice *>
>     (dev->priv);
>     > > > > +       camera->flush();
>     > > > > +
>     > > > >         return 0;
>     > > > >  }
>     > > > > 
>     >
>     > --
>     > Regards,
>     >
>     > Laurent Pinchart
> 


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