[PATCH 4.9 11/66] drm/atomic: clear out fence when duplicating state

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lucas Stach <l.stach@xxxxxxxxxxxxxx>

[Fixed differently in 4.10]

The fence needs to be cleared out, otherwise the following commit
might wait on a stale fence from the previous commit. This was fixed
as a side effect of 9626014258a5 (drm/fence: add in-fences support)
in kernel 4.10.

As this commit introduces new functionality and as such can not be
applied to stable, this patch is the minimal fix for the kernel 4.9
stable series.

Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Tested-by: Fabio Estevam <fabio.estevam@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/drm_atomic_helper.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3115,6 +3115,8 @@ void __drm_atomic_helper_plane_duplicate
 
 	if (state->fb)
 		drm_framebuffer_reference(state->fb);
+
+	state->fence = NULL;
 }
 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);