msm: mdss: Fix source split validation

The source split detection logic looks at only consecutive
layers in the layer list. This change looks at all previous
layers in the list instead of just the previous one.

Change-Id: I8b135a10ef1e5062d87c0784515a9eeb6ea4a450
Signed-off-by: Rajkumar Subbiah <rsubbia@codeaurora.org>

1 files changed, 82 insertions, 44 deletions

diff --git a/drivers/video/fbdev/msm/mdss_mdp_layer.c b/drivers/video/fbdev/msm/mdss_mdp_layer.c
index c9e32d69d444..408750a4e8da 100644
--- a/drivers/video/fbdev/msm/mdss_mdp_layer.c
+++ b/drivers/video/fbdev/msm/mdss_mdp_layer.c
@@ -2261,6 +2261,78 @@ static int __validate_multirect(struct msm_fb_data_type *mfd,
 	return 0;
 }
 
+static int __check_source_split(struct mdp_input_layer *layer_list,
+	struct mdss_mdp_pipe **pipe_list, u32 index,
+	u32 left_lm_w, struct mdss_mdp_pipe **left_blend_pipe)
+{
+	int i = index - 1;
+	struct mdp_input_layer *curr, *prev;
+	struct mdp_rect *left, *right;
+	bool match = false;
+	struct mdss_mdp_pipe *left_pipe = NULL;
+
+	/*
+	 * check if current layer is at same z_order as any of the
+	 * previous layers, and fail if any or both are async layers,
+	 * as async layers should have unique z_order.
+	 *
+	 * If it has same z_order and qualifies as a right blend,
+	 * pass a pointer to the pipe representing previous overlay or
+	 * in other terms left blend layer.
+	 *
+	 * Following logic of selecting left_blend has an inherent
+	 * assumption that layer list is sorted on dst_x within a
+	 * same z_order. Otherwise it will fail based on z_order checks.
+	 */
+	curr = &layer_list[index];
+
+	while (i >= 0) {
+		if (layer_list[i].z_order == curr->z_order) {
+			pr_debug("z=%d found match @ %d of %d\n",
+				curr->z_order, i, index);
+			match = true;
+			break;
+		}
+		i--;
+	}
+
+	if (match) {
+		left_pipe = pipe_list[i];
+		prev = &layer_list[i];
+		left = &prev->dst_rect;
+		right = &curr->dst_rect;
+
+		if ((curr->flags & MDP_LAYER_ASYNC)
+			|| (prev->flags & MDP_LAYER_ASYNC)) {
+			curr->error_code = -EINVAL;
+			pr_err("async curr should have unique z_order\n");
+			return curr->error_code;
+		}
+
+		/*
+		 * check if curr is right blend by checking it's
+		 * directly to the right.
+		 */
+		if (((left->x + left->w) == right->x) &&
+		    (left->y == right->y) && (left->h == right->h)) {
+			*left_blend_pipe = left_pipe;
+			MDSS_XLOG(curr->z_order, i, index);
+		}
+
+		/*
+		 * if the curr is right at the left lm boundary and
+		 * src split is not required then right blend is not
+		 * required as it will lie only on the left mixer
+		 */
+		if (!__layer_needs_src_split(prev) &&
+		    ((left->x + left->w) == left_lm_w))
+			*left_blend_pipe = NULL;
+	}
+
+	return 0;
+}
+
+
 /*
  * __validate_layers() - validate input layers
  * @mfd:	Framebuffer data structure for display
@@ -2291,13 +2363,14 @@ static int __validate_layers(struct msm_fb_data_type *mfd,
 	struct mdss_data_type *mdata = mfd_to_mdata(mfd);
 
 	struct mdss_mdp_mixer *mixer = NULL;
-	struct mdp_input_layer *layer, *prev_layer, *layer_list;
+	struct mdp_input_layer *layer, *layer_list;
 	struct mdss_mdp_validate_info_t *validate_info_list = NULL;
 	bool is_single_layer = false, force_validate;
 	enum layer_pipe_q pipe_q_type;
 	enum layer_zorder_used zorder_used[MDSS_MDP_MAX_STAGE] = {0};
 	enum mdss_mdp_pipe_rect rect_num;
 	struct mdp_destination_scaler_data *ds_data;
+	struct mdss_mdp_pipe *pipe_list[MAX_LAYER_COUNT] = {0};
 
 	ret = mutex_lock_interruptible(&mdp5_data->ov_lock);
 	if (ret)
@@ -2369,49 +2442,10 @@ static int __validate_layers(struct msm_fb_data_type *mfd,
 		dst_x = layer->dst_rect.x;
 		left_blend_pipe = NULL;
 
-		prev_layer = (i > 0) ? &layer_list[i - 1] : NULL;
-		/*
-		 * check if current layer is at same z_order as
-		 * previous one, and fail if any or both are async layers,
-		 * as async layers should have unique z_order.
-		 *
-		 * If it has same z_order and qualifies as a right blend,
-		 * pass a pointer to the pipe representing previous overlay or
-		 * in other terms left blend layer.
-		 *
-		 * Following logic of selecting left_blend has an inherent
-		 * assumption that layer list is sorted on dst_x within a
-		 * same z_order. Otherwise it will fail based on z_order checks.
-		 */
-		if (prev_layer && (prev_layer->z_order == layer->z_order)) {
-			struct mdp_rect *left = &prev_layer->dst_rect;
-			struct mdp_rect *right = &layer->dst_rect;
-
-			if ((layer->flags & MDP_LAYER_ASYNC)
-				|| (prev_layer->flags & MDP_LAYER_ASYNC)) {
-				ret = -EINVAL;
-				layer->error_code = ret;
-				pr_err("async layer should have unique z_order\n");
-				goto validate_exit;
-			}
-
-			/*
-			 * check if layer is right blend by checking it's
-			 * directly to the right.
-			 */
-			if (((left->x + left->w) == right->x) &&
-			    (left->y == right->y) && (left->h == right->h))
-				left_blend_pipe = pipe;
-
-			/*
-			 * if the layer is right at the left lm boundary and
-			 * src split is not required then right blend is not
-			 * required as it will lie only on the left mixer
-			 */
-			if (!__layer_needs_src_split(prev_layer) &&
-			    ((left->x + left->w) == left_lm_w))
-				left_blend_pipe = NULL;
-		}
+		if ((i > 0) &&
+		    __check_source_split(layer_list, pipe_list, i, left_lm_w,
+		    &left_blend_pipe))
+			goto validate_exit;
 
 		if (!is_split_lm(mfd) || __layer_needs_src_split(layer))
 			z = LAYER_ZORDER_BOTH;
@@ -2456,6 +2490,8 @@ static int __validate_layers(struct msm_fb_data_type *mfd,
 			else
 				left_plist[left_cnt++] = pipe;
 
+			pipe_list[i] = pipe;
+
 			if (layer->flags & MDP_LAYER_PP) {
 				memcpy(&pipe->pp_cfg, layer->pp_info,
 					sizeof(struct mdp_overlay_pp_params));
@@ -2548,6 +2584,8 @@ static int __validate_layers(struct msm_fb_data_type *mfd,
 		else
 			left_plist[left_cnt++] = pipe;
 
+		pipe_list[i] = pipe;
+
 		pr_debug("id:0x%x flags:0x%x dst_x:%d\n",
 			layer->pipe_ndx, layer->flags, layer->dst_rect.x);
 		layer->z_order -= MDSS_MDP_STAGE_0;