| Message ID | 20200605090106.15424-8-paul.elder@ideasonboard.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series |
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| Related | show |
Hi Paul, Thank you for the patch. On Fri, Jun 05, 2020 at 06:01:06PM +0900, Paul Elder wrote: > The V4L2 compatibility layer keeps track of the index of the next buffer > to be dequeued, to handle VIDIOC_DQBUF. This index is set to 0 on > startup and incremented (modulo #frames), and is otherwise never reset. > This means that if the last handled frame index is not #frames-1, and > the stream is restarted without restarting libcamera and the V4L2 > compatilibity layer, the buffer index number won't match with the > libcamera buffer index number, causing a segfault. Fix this by resetting > the current buffer index to zero on VIDIOC_STREAMON. > > Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > New in v2 > --- > src/v4l2/v4l2_camera_proxy.cpp | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp > index 7ee4c0cb..059f3cbe 100644 > --- a/src/v4l2/v4l2_camera_proxy.cpp > +++ b/src/v4l2/v4l2_camera_proxy.cpp > @@ -465,6 +465,8 @@ int V4L2CameraProxy::vidioc_streamon(int *arg) > if (!validateBufferType(*arg)) > return -EINVAL; > > + currentBuf_ = 0; > + > return vcam_->streamOn(); > } >
Hi Paul, Thanks for your work. On 2020-06-05 18:01:06 +0900, Paul Elder wrote: > The V4L2 compatibility layer keeps track of the index of the next buffer > to be dequeued, to handle VIDIOC_DQBUF. This index is set to 0 on > startup and incremented (modulo #frames), and is otherwise never reset. > This means that if the last handled frame index is not #frames-1, and > the stream is restarted without restarting libcamera and the V4L2 > compatilibity layer, the buffer index number won't match with the > libcamera buffer index number, causing a segfault. Fix this by resetting > the current buffer index to zero on VIDIOC_STREAMON. > > Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > > --- > New in v2 > --- > src/v4l2/v4l2_camera_proxy.cpp | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp > index 7ee4c0cb..059f3cbe 100644 > --- a/src/v4l2/v4l2_camera_proxy.cpp > +++ b/src/v4l2/v4l2_camera_proxy.cpp > @@ -465,6 +465,8 @@ int V4L2CameraProxy::vidioc_streamon(int *arg) > if (!validateBufferType(*arg)) > return -EINVAL; > > + currentBuf_ = 0; > + > return vcam_->streamOn(); > } > > -- > 2.20.1 > > _______________________________________________ > libcamera-devel mailing list > libcamera-devel@lists.libcamera.org > https://lists.libcamera.org/listinfo/libcamera-devel
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp index 7ee4c0cb..059f3cbe 100644 --- a/src/v4l2/v4l2_camera_proxy.cpp +++ b/src/v4l2/v4l2_camera_proxy.cpp @@ -465,6 +465,8 @@ int V4L2CameraProxy::vidioc_streamon(int *arg) if (!validateBufferType(*arg)) return -EINVAL; + currentBuf_ = 0; + return vcam_->streamOn(); }
The V4L2 compatibility layer keeps track of the index of the next buffer to be dequeued, to handle VIDIOC_DQBUF. This index is set to 0 on startup and incremented (modulo #frames), and is otherwise never reset. This means that if the last handled frame index is not #frames-1, and the stream is restarted without restarting libcamera and the V4L2 compatilibity layer, the buffer index number won't match with the libcamera buffer index number, causing a segfault. Fix this by resetting the current buffer index to zero on VIDIOC_STREAMON. Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> --- New in v2 --- src/v4l2/v4l2_camera_proxy.cpp | 2 ++ 1 file changed, 2 insertions(+)