drm/sti: do not post HQVDP command if no update

Do not process update requests with unmodified parameters.

Since the HQVDP command queue is limited to 2, we shall take care of
not posting unneeded commands, which would abusively fill the command
queue leading to frame update skip.
This typically happens when the driver is called with legacy
(non-atomic) IOCTL : in that case atomic_update() is called multiple
times with the same parameters.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

diff --git a/drivers/gpu/drm/sti/sti_hqvdp.c b/drivers/gpu/drm/sti/sti_hqvdp.c
index a547723bc7d2c41aeec87dec6ee6580fedf2864c..55cbaea1d49d7b1c9d1f15b90cb3cd65b4ede449 100644 (file)
--- a/drivers/gpu/drm/sti/sti_hqvdp.c
+++ b/drivers/gpu/drm/sti/sti_hqvdp.c
@@ -1117,6 +1117,21 @@ static void sti_hqvdp_atomic_update(struct drm_plane *drm_plane,
        if (!crtc || !fb)
                return;
 
+       if ((oldstate->fb == state->fb) &&
+           (oldstate->crtc_x == state->crtc_x) &&
+           (oldstate->crtc_y == state->crtc_y) &&
+           (oldstate->crtc_w == state->crtc_w) &&
+           (oldstate->crtc_h == state->crtc_h) &&
+           (oldstate->src_x == state->src_x) &&
+           (oldstate->src_y == state->src_y) &&
+           (oldstate->src_w == state->src_w) &&
+           (oldstate->src_h == state->src_h)) {
+               /* No change since last update, do not post cmd */
+               DRM_DEBUG_DRIVER("No change, not posting cmd\n");
+               plane->status = STI_PLANE_UPDATED;
+               return;
+       }
+
        mode = &crtc->mode;
        dst_x = state->crtc_x;
        dst_y = state->crtc_y;