i965_drv_video: clear draw buffer before rendering.

i965_drv_video/i965_render.c

@@ -1212,11 +1212,53 @@ i965_render_startup(VADriverContextP ctx)
     ADVANCE_BATCH(ctx);
 }
 
+static void 
+i965_clear_dest_region(VADriverContextP ctx)
+{
+    struct i965_driver_data *i965 = i965_driver_data(ctx);  
+    struct i965_render_state *render_state = &i965->render_state;
+    struct intel_region *dest_region = render_state->draw_region;
+    unsigned int blt_cmd, br13;
+    int pitch;
+
+    blt_cmd = XY_COLOR_BLT_CMD;
+    br13 = 0xf0 << 16;
+    pitch = dest_region->pitch;
+
+    if (dest_region->cpp == 4) {
+        br13 |= BR13_8888;
+        blt_cmd |= (XY_COLOR_BLT_WRITE_RGB | XY_COLOR_BLT_WRITE_ALPHA);
+    } else {
+        assert(dest_region->cpp == 2);
+        br13 |= BR13_565;
+    }
+
+    if (dest_region->tiling != I915_TILING_NONE) {
+        blt_cmd |= XY_COLOR_BLT_DST_TILED;
+        pitch /= 4;
+    }
+
+    br13 |= pitch;
+
+    BEGIN_BATCH(ctx, 6);
+    OUT_BATCH(ctx, blt_cmd);
+    OUT_BATCH(ctx, br13);
+    OUT_BATCH(ctx, (dest_region->y << 16) | (dest_region->x));
+    OUT_BATCH(ctx, ((dest_region->y + dest_region->height) << 16) |
+              (dest_region->x + dest_region->width));
+    OUT_RELOC(ctx, dest_region->bo, 
+              I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER,
+              0);
+    OUT_BATCH(ctx, 0x0);
+    ADVANCE_BATCH(ctx);
+}
+
 static void
 i965_surface_render_pipeline_setup(VADriverContextP ctx)
 {
     intel_batchbuffer_start_atomic(ctx, 0x1000);
     intel_batchbuffer_emit_mi_flush(ctx);
+    i965_clear_dest_region(ctx);
     i965_render_pipeline_select(ctx);
     i965_render_state_sip(ctx);
     i965_render_state_base_address(ctx);

i965_drv_video/intel_driver.h

@@ -21,6 +21,7 @@
 #define BATCH_RESERVED  0x10
 
 #define CMD_MI                                  (0x0 << 29)
+#define CMD_2D                                  (0x2 << 29)
 
 #define MI_NOOP                                 (CMD_MI | 0)
 
@@ -29,6 +30,15 @@
 #define MI_FLUSH                                (CMD_MI | (0x4 << 23))
 #define STATE_INSTRUCTION_CACHE_INVALIDATE      (0x1 << 0)
 
+#define XY_COLOR_BLT_CMD                        (CMD_2D | (0x50 << 22) | 0x04)
+#define XY_COLOR_BLT_WRITE_ALPHA                (1 << 21)
+#define XY_COLOR_BLT_WRITE_RGB                  (1 << 20)
+#define XY_COLOR_BLT_DST_TILED                  (1 << 11)
+
+/* BR13 */
+#define BR13_565                                (0x1 << 24)
+#define BR13_8888                               (0x3 << 24)
+
 struct intel_batchbuffer;
 
 #define ALIGN(i, n)    (((i) + (n) - 1) & ~((n) - 1))