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[PATCH/RFC,13/48] v4l: vsp1: Document calling context of vsp1_pipeline_propagate_alpha()

Message ID 1450341626-6695-14-git-send-email-laurent.pinchart+renesas@ideasonboard.com (mailing list archive)
State RFC
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Laurent Pinchart Dec. 17, 2015, 8:39 a.m. UTC
The function can only be called from a s_stream handler as it requires a
valid display list context (due to calling vsp1_uds_set_alpha() which
writes to module registers). Document the requirement.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 drivers/media/platform/vsp1/vsp1_pipe.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox

Patch

diff --git a/drivers/media/platform/vsp1/vsp1_pipe.c b/drivers/media/platform/vsp1/vsp1_pipe.c
index facf68f999ce..9549aacab3cf 100644
--- a/drivers/media/platform/vsp1/vsp1_pipe.c
+++ b/drivers/media/platform/vsp1/vsp1_pipe.c
@@ -297,6 +297,9 @@  done:
  * to be scaled, we disable alpha scaling when the UDS input has a fixed alpha
  * value. The UDS then outputs a fixed alpha value which needs to be programmed
  * from the input RPF alpha.
+ *
+ * This function can only be called from a subdev s_stream handler as it
+ * requires a valid display list context.
  */
 void vsp1_pipeline_propagate_alpha(struct vsp1_pipeline *pipe,
 				   struct vsp1_entity *input,