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.

diff --git a/src/gallium/drivers/r600/r600_texture.c b/src/gallium/drivers/r600/r600_texture.c
index 02160fd..ef5adaf 100644 (file)
--- 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);