gallium: fix some surface usage bugs

When a surface is created with GPU_WRITE that really means "GPU render"
and that can involve reads (blending).  Set surface usage to
PIPE_BUFFER_USAGE_CPU_READ + WRITE.  Fixes progs/demos/lodbias demo.

Also, mark texture as 'modified' when mapped for writing so that the tile
cache can know when to freshen a cached tile.  Fixes glTexSubImage2D().

3 files changed, 21 insertions, 2 deletions

diff --git a/src/gallium/drivers/softpipe/sp_texture.c b/src/gallium/drivers/softpipe/sp_texture.c
index 1d7a1fffe4d..ef8c5bd6b0c 100644
--- a/src/gallium/drivers/softpipe/sp_texture.c
+++ b/src/gallium/drivers/softpipe/sp_texture.c
@@ -207,12 +207,19 @@ softpipe_get_tex_surface(struct pipe_screen *screen,
        * done with the CPU.  Let's adjust the flags to take that into
        * account.
        */
-      if (ps->usage & PIPE_BUFFER_USAGE_GPU_WRITE)
-         ps->usage |= PIPE_BUFFER_USAGE_CPU_WRITE;
+      if (ps->usage & PIPE_BUFFER_USAGE_GPU_WRITE) {
+         /* GPU_WRITE means "render" and that can involve reads (blending) */
+         ps->usage |= PIPE_BUFFER_USAGE_CPU_WRITE | PIPE_BUFFER_USAGE_CPU_READ;
+      }
 
       if (ps->usage & PIPE_BUFFER_USAGE_GPU_READ)
          ps->usage |= PIPE_BUFFER_USAGE_CPU_READ;
 
+      if (ps->usage & (PIPE_BUFFER_USAGE_CPU_WRITE |
+                       PIPE_BUFFER_USAGE_GPU_WRITE)) {
+         /* Mark the surface as dirty.  The tile cache will look for this. */
+         spt->modified = TRUE;
+      }
 
       pipe_texture_reference(&ps->texture, pt); 
       ps->face = face;
diff --git a/src/gallium/drivers/softpipe/sp_texture.h b/src/gallium/drivers/softpipe/sp_texture.h
index 779a9d8fc97..0e1017632c9 100644
--- a/src/gallium/drivers/softpipe/sp_texture.h
+++ b/src/gallium/drivers/softpipe/sp_texture.h
@@ -47,6 +47,8 @@ struct softpipe_texture
    /* The data is held here:
     */
    struct pipe_buffer *buffer;
+
+   boolean modified;
 };
 
 
diff --git a/src/gallium/drivers/softpipe/sp_tile_cache.c b/src/gallium/drivers/softpipe/sp_tile_cache.c
index 0e4c8c41eea..2d5d2b50f51 100644
--- a/src/gallium/drivers/softpipe/sp_tile_cache.c
+++ b/src/gallium/drivers/softpipe/sp_tile_cache.c
@@ -37,6 +37,7 @@
 #include "util/p_tile.h"
 #include "sp_context.h"
 #include "sp_surface.h"
+#include "sp_texture.h"
 #include "sp_tile_cache.h"
 
 #define NUM_ENTRIES 32
@@ -506,6 +507,15 @@ sp_get_cached_tile_tex(struct pipe_context *pipe,
                                   face, level);
    struct softpipe_cached_tile *tile = tc->entries + pos;
 
+   if (tc->texture) {
+      struct softpipe_texture *spt = softpipe_texture(tc->texture);
+      if (spt->modified) {
+         /* texture was modified, force a cache reload */
+         tile->x = -1;
+         spt->modified = FALSE;
+      }
+   }
+
    if (tile_x != tile->x ||
        tile_y != tile->y ||
        z != tile->z ||