[PATCH 05/31] media: Media Controller fix to not let stream_count go negative
From: Shuah Khan <hidden>
Date: 2016-01-06 20:36:01
Also in:
alsa-devel, linux-media, lkml
Subsystem:
media input infrastructure (v4l/dvb), the rest · Maintainers:
Mauro Carvalho Chehab, Linus Torvalds
Add a range check to not let the stream_count become negative. Wthout this check, calls to stop pipeline when there is no active pipeline will result in stream_count < 0 condition and lock and preventing link state (activate/deactivate) changes. This will happen from error leg in start pipeline interface. Signed-off-by: Shuah Khan <redacted> --- drivers/media/media-entity.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c
index 6e02d19..78486a9 100644
--- a/drivers/media/media-entity.c
+++ b/drivers/media/media-entity.c@@ -464,9 +464,12 @@ error: media_entity_graph_walk_start(graph, entity_err); while ((entity_err = media_entity_graph_walk_next(graph))) { - entity_err->stream_count--; - if (entity_err->stream_count == 0) - entity_err->pipe = NULL; + /* don't let the stream_count go negative */ + if (entity->stream_count > 0) { + entity_err->stream_count--; + if (entity_err->stream_count == 0) + entity_err->pipe = NULL; + } /* * We haven't increased stream_count further than this
@@ -498,9 +501,12 @@ void media_entity_pipeline_stop(struct media_entity *entity) media_entity_graph_walk_start(graph, entity); while ((entity = media_entity_graph_walk_next(graph))) { - entity->stream_count--; - if (entity->stream_count == 0) - entity->pipe = NULL; + /* don't let the stream_count go negative */ + if (entity->stream_count > 0) { + entity->stream_count--; + if (entity->stream_count == 0) + entity->pipe = NULL; + } } if (!--pipe->streaming_count)
--
2.5.0