sna: Do not undo a bo if we may fallback

If we undo the pending operations to a bo, then fallback we cause
corruption. For example, see wine and its 1-bit rendering.

Fixes regression from
commit 07a4400fffe4f83df3debe62abd2c37b45f8f0c0 [2.21.7]
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri May 10 11:59:59 2013 +0100

    sna: Attempt to discard overwritten operations before CopyArea

Also we need to be more careful and consider alu when marking the
operation as 'replaces'.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 24 insertions, 9 deletions

diff --git a/src/sna/sna_accel.c b/src/sna/sna_accel.c
index f795dfbd..d0a48b23 100644
--- a/src/sna/sna_accel.c
+++ b/src/sna/sna_accel.c
@@ -4600,6 +4600,7 @@ sna_copy_boxes(DrawablePtr src, DrawablePtr dst, GCPtr gc,
 					       src_dx, src_dy);
 
 	replaces = n == 1 &&
+		alu_overwrites(alu) &&
 		box->x1 <= 0 &&
 		box->y1 <= 0 &&
 		box->x2 >= dst_pixmap->drawable.width &&
@@ -4649,13 +4650,13 @@ sna_copy_boxes(DrawablePtr src, DrawablePtr dst, GCPtr gc,
 		bo = sna_drawable_use_bo(&dst_pixmap->drawable, hint,
 					 &region->extents, &damage);
 	if (bo) {
-		if (replaces)
-			kgem_bo_undo(&sna->kgem, bo);
-
 		if (src_priv && src_priv->clear) {
 			DBG(("%s: applying src clear[%08x] to dst\n",
 			     __FUNCTION__, src_priv->clear_color));
 			if (n == 1) {
+				if (replaces)
+					kgem_bo_undo(&sna->kgem, bo);
+
 				if (!sna->render.fill_one(sna,
 							  dst_pixmap, bo,
 							  src_priv->clear_color,
@@ -4666,6 +4667,16 @@ sna_copy_boxes(DrawablePtr src, DrawablePtr dst, GCPtr gc,
 					     __FUNCTION__));
 					goto fallback;
 				}
+
+				if (replaces && bo == dst_priv->gpu_bo) {
+					dst_priv->clear = true;
+					dst_priv->clear_color = src_priv->clear_color;
+					sna_damage_all(&dst_priv->gpu_damage,
+						       dst_pixmap->drawable.width,
+						       dst_pixmap->drawable.height);
+					sna_damage_destroy(&dst_priv->cpu_damage);
+					list_del(&dst_priv->flush_list);
+				}
 			} else {
 				struct sna_fill_op fill;
 
@@ -4681,11 +4692,6 @@ sna_copy_boxes(DrawablePtr src, DrawablePtr dst, GCPtr gc,
 				fill.done(sna, &fill);
 			}
 
-			if (replaces && bo == dst_priv->gpu_bo) {
-				dst_priv->clear = true;
-				dst_priv->clear_color = src_priv->clear_color;
-			}
-
 			if (damage)
 				sna_damage_add(damage, region);
 			return;
@@ -4696,7 +4702,10 @@ sna_copy_boxes(DrawablePtr src, DrawablePtr dst, GCPtr gc,
 		    sna_pixmap_move_to_gpu(src_pixmap, MOVE_READ | MOVE_ASYNC_HINT)) {
 			DBG(("%s: move whole src_pixmap to GPU and copy\n",
 			     __FUNCTION__));
-			if (replaces &&
+			if (replaces)
+				kgem_bo_undo(&sna->kgem, bo);
+
+			if (replaces && alu == GXcopy &&
 			    src_pixmap->drawable.width == dst_pixmap->drawable.width &&
 			    src_pixmap->drawable.height == dst_pixmap->drawable.height) {
 				assert(src_pixmap->drawable.depth == dst_pixmap->drawable.depth);
@@ -4745,6 +4754,9 @@ sna_copy_boxes(DrawablePtr src, DrawablePtr dst, GCPtr gc,
 							 MOVE_READ | MOVE_ASYNC_HINT))
 				goto fallback;
 
+			if (replaces)
+				kgem_bo_undo(&sna->kgem, bo);
+
 			if (!sna->render.copy_boxes(sna, alu,
 						    src_pixmap, src_priv->gpu_bo, src_dx, src_dy,
 						    dst_pixmap, bo, 0, 0,
@@ -4778,6 +4790,9 @@ sna_copy_boxes(DrawablePtr src, DrawablePtr dst, GCPtr gc,
 			if (!ret)
 				goto fallback;
 
+			if (replaces)
+				kgem_bo_undo(&sna->kgem, bo);
+
 			if (src_priv->shm) {
 				assert(!src_priv->flush);
 				sna_add_flush_pixmap(sna, src_priv, src_priv->cpu_bo);