[libcamera-devel] [PATCH 13/15] v4l2: v4l2_camera: Clear pending requests on freeBuffers

[Jacopo Mondi]

Hi Paul,

On Tue, Jun 16, 2020 at 10:12:42PM +0900, Paul Elder wrote:
> V4L2 allows buffer queueing before streamon while libcamera does not.
> The compatibility layer thus saves these buffers in a pending queue
> until streamon, and then automatically queues them. However, this
> pending queue is not cleared when the buffers a freed, so if buffers are

s/a freed/are freed.

> queued, the stream is not started, buffers are freed, more buffers are
> queued, and the stream is finally started, then the first set of buffers
> will be used-after-free. Fix this by clearing the pending quest queue
> upon the buffers being freed.
>
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>

Should this happen at streamoff time as well ?
Got a bit lost :)

Otherwise
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
  j

> ---
>  src/v4l2/v4l2_camera.cpp | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/src/v4l2/v4l2_camera.cpp b/src/v4l2/v4l2_camera.cpp
> index f0ec54b..bae270a 100644
> --- a/src/v4l2/v4l2_camera.cpp
> +++ b/src/v4l2/v4l2_camera.cpp
> @@ -155,6 +155,7 @@ void V4L2Camera::freeBuffers()
>  	Stream *stream = *camera_->streams().begin();
>
>  	bufferAllocator_->free(stream);
> +	pendingRequests_.clear();
>  }
>
>  FileDescriptor V4L2Camera::getBufferFd(unsigned int index)
> --
> 2.27.0
>
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