drm: rcar-du: Track dma-buf fences

We have to check dma-buf reservation objects of our framebuffers before
we use them. Otherwise, another driver might be writing on the same
buffer which we are using. This would cause visible tearing effects
on display.

We can use existing atomic helper functions to solve this problem.

Signed-off-by: Emre Ucan <[email protected]>
Reviewed-by: Laurent Pinchart <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Signed-off-by: Laurent Pinchart <[email protected]>

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
index 4a01a99a46745c149b4d6a527e61b7c4ad9b1ec5..3badf02ab24aee33655584d61675b56b7934756b 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
@@ -17,6 +17,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_plane_helper.h>
 
 #include <linux/bitops.h>
@@ -237,6 +238,10 @@ static int rcar_du_vsp_plane_prepare_fb(struct drm_plane *plane,
                }
        }
 
+       ret = drm_gem_fb_prepare_fb(plane, state);
+       if (ret)
+               goto fail;
+
        return 0;
 
 fail: