fix miptree comparison with compressed textures

TexelBytes is always 0 with compressed textures, thus would never match
mt->cpp. This caused constant blitting around of textures, and it fixes at
least the horrible performance of Q3 if compressed textures are enabled.

src/mesa/drivers/dri/i915tex/intel_tex_validate.c

@@ -105,6 +105,8 @@ intel_finalize_mipmap_tree(struct intel_context *intel, GLuint unit)
 {
    struct gl_texture_object *tObj = intel->ctx.Texture.Unit[unit]._Current;
    struct intel_texture_object *intelObj = intel_texture_object(tObj);
+   int comp_byte = 0;
+   int cpp;
 
    GLuint face, i;
    GLuint nr_faces = 0;
@@ -148,6 +150,12 @@ intel_finalize_mipmap_tree(struct intel_context *intel, GLuint unit)
       intel_miptree_reference(&intelObj->mt, firstImage->mt);
    }
 
+   if (firstImage->base.IsCompressed) {
+      comp_byte = intel_compressed_num_bytes(firstImage->base.TexFormat->MesaFormat);
+      cpp = comp_byte;
+   }
+   else cpp = firstImage->base.TexFormat->TexelBytes;
+
    /* Check tree can hold all active levels.  Check tree matches
     * target, imageFormat, etc.
     * 
@@ -165,7 +173,7 @@ intel_finalize_mipmap_tree(struct intel_context *intel, GLuint unit)
 	intelObj->mt->width0 != firstImage->base.Width ||
 	intelObj->mt->height0 != firstImage->base.Height ||
 	intelObj->mt->depth0 != firstImage->base.Depth ||
-	intelObj->mt->cpp != firstImage->base.TexFormat->TexelBytes ||
+	intelObj->mt->cpp != cpp ||
 	intelObj->mt->compressed != firstImage->base.IsCompressed)) {
       intel_miptree_release(intel, &intelObj->mt);
    }
@@ -174,10 +182,6 @@ intel_finalize_mipmap_tree(struct intel_context *intel, GLuint unit)
    /* May need to create a new tree:
     */
    if (!intelObj->mt) {
-      int comp_byte = 0;
-      
-      if (firstImage->base.IsCompressed)
-	 comp_byte = intel_compressed_num_bytes(firstImage->base.TexFormat->MesaFormat);
       intelObj->mt = intel_miptree_create(intel,
                                           intelObj->base.Target,
                                           firstImage->base.InternalFormat,
@@ -186,8 +190,7 @@ intel_finalize_mipmap_tree(struct intel_context *intel, GLuint unit)
                                           firstImage->base.Width,
                                           firstImage->base.Height,
                                           firstImage->base.Depth,
-                                          firstImage->base.TexFormat->
-                                          TexelBytes,
+                                          cpp,
                                           comp_byte);
    }