[PATCH v2 1/6] drm/vc4: Make vc4_lbm_size() return 0 when vertical scaling is disabled

[Boris Brezillon]

LBM is not needed when vertical scaling is disabled. Return 0 in this
case to avoid allocating LBM memory that will anyway be unused.

While at it, drop the test on ->is_unity which is now redundant.

Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>
Reviewed-by: Eric Anholt <eric at anholt.net>
---
Changes in v2:
- Add Eric R-b
---
 drivers/gpu/drm/vc4/vc4_plane.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index c3ded0ba0441..f6e3e8d33115 100644
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -395,10 +395,13 @@ static u32 vc4_lbm_size(struct drm_plane_state *state)
 	u32 pix_per_line = max(vc4_state->src_w[0], (u32)vc4_state->crtc_w);
 	u32 lbm;
 
+	/* LBM is not needed when there's no vertical scaling. */
+	if (vc4_state->y_scaling[0] == VC4_SCALING_NONE &&
+	    vc4_state->y_scaling[1] == VC4_SCALING_NONE)
+		return 0;
+
 	if (!vc4_state->is_yuv) {
-		if (vc4_state->is_unity)
-			return 0;
-		else if (vc4_state->y_scaling[0] == VC4_SCALING_TPZ)
+		if (vc4_state->y_scaling[0] == VC4_SCALING_TPZ)
 			lbm = pix_per_line * 8;
 		else {
 			/* In special cases, this multiplier might be 12. */
-- 
2.17.1