From c0bad607ce16ea66aa9c4de892598793402281c6 Mon Sep 17 00:00:00 2001 From: Kieran Bingham Date: Tue, 12 Jan 2021 10:21:39 +0530 Subject: libcamera: v4l2_videodevice: Track streaming state Track the state of streamon/streamoff calls to simplify error paths. Ensuring that streamOff() can be called on non-streaming streams facilitates simpler error code paths, where a set of devices can all call streamOff regardless of their initialisation state. Signed-off-by: Kieran Bingham Signed-off-by: Umang Jain Reviewed-by: Kieran Bingham Reviewed-by: Laurent Pinchart Signed-off-by: Kieran Bingham --- src/libcamera/v4l2_videodevice.cpp | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'src/libcamera/v4l2_videodevice.cpp') diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index baf683d6..a9509bff 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -481,7 +481,8 @@ const std::string V4L2DeviceFormat::toString() const * \param[in] deviceNode The file-system path to the video device node */ V4L2VideoDevice::V4L2VideoDevice(const std::string &deviceNode) - : V4L2Device(deviceNode), cache_(nullptr), fdBufferNotifier_(nullptr) + : V4L2Device(deviceNode), cache_(nullptr), fdBufferNotifier_(nullptr), + streaming_(false) { /* * We default to an MMAP based CAPTURE video device, however this will @@ -1554,6 +1555,8 @@ int V4L2VideoDevice::streamOn() return ret; } + streaming_ = true; + return 0; } @@ -1565,12 +1568,18 @@ int V4L2VideoDevice::streamOn() * and the bufferReady signal is emitted for them. The order in which those * buffers are dequeued is not specified. * + * This will be a no-op if the stream is not started in the first place and + * has no queued buffers. + * * \return 0 on success or a negative error code otherwise */ int V4L2VideoDevice::streamOff() { int ret; + if (!streaming_ && queuedBuffers_.empty()) + return 0; + ret = ioctl(VIDIOC_STREAMOFF, &bufferType_); if (ret < 0) { LOG(V4L2, Error) @@ -1588,6 +1597,7 @@ int V4L2VideoDevice::streamOff() queuedBuffers_.clear(); fdBufferNotifier_->setEnabled(false); + streaming_ = false; return 0; } -- cgit v1.2.1