Mesa (master): r600: fix my pessimism about PIPE_TRANSFER_x flags

[Keith Whitwell]

Module: Mesa
Branch: master
Commit: 63c3e3a3dc73f8a72e0d08ac4453df57bccdfdb9
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=63c3e3a3dc73f8a72e0d08ac4453df57bccdfdb9

Author: Keith Whitwell <keithw at vmware.com>
Date:   Tue Nov  9 20:08:45 2010 +0000

r600: fix my pessimism about PIPE_TRANSFER_x flags

For some reason I though we needed the _DISCARD flag to avoid
readbacks, which isn't true at all.  Now write operations should
pipeline properly, gives a good speedup to demos/tunnel.

---

 src/gallium/drivers/r600/r600_texture.c |   13 +++++--------
 1 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/gallium/drivers/r600/r600_texture.c b/src/gallium/drivers/r600/r600_texture.c
index 02160fd..ef5adaf 100644
--- a/src/gallium/drivers/r600/r600_texture.c
+++ b/src/gallium/drivers/r600/r600_texture.c
@@ -507,10 +507,6 @@ struct pipe_transfer* r600_texture_get_transfer(struct pipe_context *ctx,
 	struct r600_transfer *trans;
 	int r;
 	boolean use_staging_texture = FALSE;
-	boolean discard = FALSE;
-
-	if (!(usage & PIPE_TRANSFER_READ) && (usage & PIPE_TRANSFER_DISCARD))
-		discard = TRUE;
 
 	/* We cannot map a tiled texture directly because the data is
 	 * in a different order, therefore we do detiling using a blit.
@@ -522,7 +518,7 @@ struct pipe_transfer* r600_texture_get_transfer(struct pipe_context *ctx,
 	if (rtex->tiled)
 		use_staging_texture = TRUE;
 
-        if (usage & PIPE_TRANSFER_READ &&
+	if ((usage & PIPE_TRANSFER_READ) &&
             u_box_volume(box) > 1024)
                 use_staging_texture = TRUE;
 
@@ -532,8 +528,9 @@ struct pipe_transfer* r600_texture_get_transfer(struct pipe_context *ctx,
          * and might block.
          */
         if ((usage & PIPE_TRANSFER_WRITE) &&
-            discard &&
-            !(usage & (PIPE_TRANSFER_DONTBLOCK | PIPE_TRANSFER_UNSYNCHRONIZED)))
+            !(usage & (PIPE_TRANSFER_READ |
+                       PIPE_TRANSFER_DONTBLOCK |
+                       PIPE_TRANSFER_UNSYNCHRONIZED)))
                 use_staging_texture = TRUE;
 
         if (!permit_hardware_blit(ctx->screen, texture) ||
@@ -591,7 +588,7 @@ struct pipe_transfer* r600_texture_get_transfer(struct pipe_context *ctx,
 
 		trans->transfer.stride =
                         ((struct r600_resource_texture *)trans->staging_texture)->pitch_in_bytes[0];
-		if (!discard) {
+		if (usage & PIPE_TRANSFER_READ) {
 			r600_copy_to_staging_texture(ctx, trans);
 			/* Always referenced in the blit. */
 			ctx->flush(ctx, 0, NULL);