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.
v2 changes: - Remove drm_atomic_helper_wait_for_fences() call in rcar_du_kms.c. The commit_tail() function in drm_atomic_helper.c, which calls our atomic_commit_tail() implementation, already calls it. - Remove proposed rcar_du_vsp_set_fence_for_plane() function. Call drm_gem_fb_prepare_fb(), which calls drm_atomic_set_fence_for_plane().
v3 changes: - Sort the added header file alphabetically. - Check return value of drm_gem_fb_prepare_fb() and clean up in the case of error.
Signed-off-by: Emre Ucan eucan@de.adit-jv.com --- drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c index 2c260c3..73c7948 100644 --- 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: