openwrt/target/linux/bcm27xx/patches-5.4/950-0540-drm-vc4-plane-Improve-LBM-usage.patch

From 81072e19a85bfa3f80c23acdff6156522d945efa Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Tue, 11 Feb 2020 16:55:02 +0000
Subject: [PATCH] drm/vc4: plane: Improve LBM usage

LBM allocations were always taking the worst case sizing of
max(src_width, dst_width) * 16. This is significantly over
the required sizing, and stops us rendering multiple 4k images
to the screen.

Add some of the additional constraints to more accurately
describe the LBM requirements.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_plane.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -142,9 +142,10 @@ static const struct hvs_format *vc4_get_
 	return NULL;
 }
 
-static enum vc4_scaling_mode vc4_get_scaling_mode(u32 src, u32 dst)
+static enum vc4_scaling_mode vc4_get_scaling_mode(u32 src, u32 dst,
+						  bool chroma_vrep)
 {
-	if (dst == src)
+	if (dst == src && !chroma_vrep)
 		return VC4_SCALING_NONE;
 	if (3 * dst >= 2 * src)
 		return VC4_SCALING_PPF;
@@ -377,9 +378,11 @@ static int vc4_plane_setup_clipping_and_
 		return ret;
 
 	vc4_state->x_scaling[0] = vc4_get_scaling_mode(vc4_state->src_w[0],
-						       vc4_state->crtc_w);
+						       vc4_state->crtc_w,
+						       false);
 	vc4_state->y_scaling[0] = vc4_get_scaling_mode(vc4_state->src_h[0],
-						       vc4_state->crtc_h);
+						       vc4_state->crtc_h,
+						       false);
 
 	vc4_state->is_unity = (vc4_state->x_scaling[0] == VC4_SCALING_NONE &&
 			       vc4_state->y_scaling[0] == VC4_SCALING_NONE);
@@ -392,10 +395,12 @@ static int vc4_plane_setup_clipping_and_
 
 		vc4_state->x_scaling[1] =
 			vc4_get_scaling_mode(vc4_state->src_w[1],
-					     vc4_state->crtc_w);
+					     vc4_state->crtc_w,
+					     v_subsample == 2);
 		vc4_state->y_scaling[1] =
 			vc4_get_scaling_mode(vc4_state->src_h[1],
-					     vc4_state->crtc_h);
+					     vc4_state->crtc_h,
+					     v_subsample == 2);
 
 		/* YUV conversion requires that horizontal scaling be enabled
 		 * on the UV plane even if vc4_get_scaling_mode() returned
@@ -445,10 +450,7 @@ static void vc4_write_ppf(struct vc4_pla
 static u32 vc4_lbm_size(struct drm_plane_state *state)
 {
 	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
-	/* This is the worst case number.  One of the two sizes will
-	 * be used depending on the scaling configuration.
-	 */
-	u32 pix_per_line = max(vc4_state->src_w[0], (u32)vc4_state->crtc_w);
+	u32 pix_per_line;
 	u32 lbm;
 
 	/* LBM is not needed when there's no vertical scaling. */
@@ -456,6 +458,11 @@ static u32 vc4_lbm_size(struct drm_plane
 	    vc4_state->y_scaling[1] == VC4_SCALING_NONE)
 		return 0;
 
+	if (vc4_state->x_scaling[0] == VC4_SCALING_TPZ)
+		pix_per_line = vc4_state->crtc_w;
+	else
+		pix_per_line = vc4_state->src_w[0];
+
 	if (!vc4_state->is_yuv) {
 		if (vc4_state->y_scaling[0] == VC4_SCALING_TPZ)
 			lbm = pix_per_line * 8;
@@ -591,7 +598,9 @@ static int vc4_plane_allocate_lbm(struct
 		spin_lock_irqsave(&vc4->hvs->mm_lock, irqflags);
 		ret = drm_mm_insert_node_generic(&vc4->hvs->lbm_mm,
 						 &vc4_state->lbm,
-						 lbm_size, 32, 0, 0);
+						 lbm_size,
+						 vc4->hvs->hvs5 ? 64 : 32,
+						 0, 0);
 		spin_unlock_irqrestore(&vc4->hvs->mm_lock, irqflags);
 
 		if (ret)