This fixes a possible deadlock between gst_v4l2_video_dec_change_state
and gst_v4l2_video_dec_loop on the buffer pool.
When stopping capture, the flushing state of the v4l2 capture buffer
pool gets reverted in the processing loop after it was set via
gst_v4l2_object_unlock (self->v4l2capture) (in
gst_v4l2_video_dec_change_state). As a result, gst_v4l2_video_dec_loop
does not return and consequently, gst_pad_stop_task gets stuck waiting
for the GST_PAD_STREAM_LOCK. To circumvent this, skip acquiring the
buffer pool if stopping capture.
Suggested-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7958>
225d6b7e11