DRI2: Debugging code for testing the frames order correctness

If DEBUG_WITH_RGB_PATTERN is defined, then we check that the
frames colors are changed as "R -> G -> B -> R -> G -> ..."
pattern and print debugging messages when this is not the
case. Such color change pattern can be generated by the
"test/gles-rgb-cycle-demo.c" program.
Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

src/sunxi_mali_ump_dri2.c

@@ -566,6 +566,47 @@ static void FlushOverlay(ScreenPtr pScreen)
     }
 }
 
+#ifdef DEBUG_WITH_RGB_PATTERN
+static void check_rgb_pattern(DRI2WindowStatePtr window_state,
+                              UMPBufferInfoPtr umpbuf)
+{
+    switch (*(uint32_t *)(umpbuf->addr + umpbuf->offs)) {
+    case 0xFFFF0000:
+        if (window_state->rgb_pattern_state == 0) {
+            ErrorF("starting RGB pattern with [Red]\n");
+        }
+        else if (window_state->rgb_pattern_state != 'B') {
+            ErrorF("warning - transition to [Red] not from [Blue]\n");
+        }
+        window_state->rgb_pattern_state = 'R';
+        break;
+    case 0xFF00FF00:
+        if (window_state->rgb_pattern_state == 0) {
+            ErrorF("starting RGB pattern with [Green]\n");
+        }
+        else if (window_state->rgb_pattern_state != 'R') {
+            ErrorF("warning - transition to [Green] not from [Red]\n");
+        }
+        window_state->rgb_pattern_state = 'G';
+        break;
+    case 0xFF0000FF:
+        if (window_state->rgb_pattern_state == 0) {
+            ErrorF("starting RGB pattern with [Blue]\n");
+        }
+        else if (window_state->rgb_pattern_state != 'G') {
+            ErrorF("warning - transition to [Blue] not from [Green]\n");
+        }
+        window_state->rgb_pattern_state = 'B';
+        break;
+    default:
+        if (window_state->rgb_pattern_state != 0) {
+            ErrorF("stopping RGB pattern\n");
+        }
+        window_state->rgb_pattern_state = 0;
+    }
+}
+#endif
+
 static void MaliDRI2CopyRegion(DrawablePtr   pDraw,
                                RegionPtr     pRegion,
                                DRI2BufferPtr pDstBuffer,
@@ -607,6 +648,10 @@ static void MaliDRI2CopyRegion(DrawablePtr   pDraw,
     if (!umpbuf || !umpbuf->addr)
         return;
 
+#ifdef DEBUG_WITH_RGB_PATTERN
+    check_rgb_pattern(window_state, umpbuf);
+#endif
+
     UpdateOverlay(pScreen);
 
     if (!drvpriv->bOverlayWinEnabled || umpbuf->handle != UMP_INVALID_MEMORY_HANDLE) {

src/sunxi_mali_ump_dri2.h

@@ -97,6 +97,18 @@ typedef struct
     UMPBufferInfoPtr        ump_queue[16];
     int                     ump_queue_head;
     int                     ump_queue_tail;
+
+    /*
+     * In the case DEBUG_WITH_RGB_PATTERN is defined, we add extra debugging
+     * code for verifying that for each new frame, the background color is
+     * changed as "R -> G -> B -> R -> G -> B -> ..." pattern and there are
+     * no violations of this color change order. It is intended to be used
+     * together with "test/gles-rgb-cycle-demo.c" program, which can generate
+     * such pattern.
+     */
+#ifdef DEBUG_WITH_RGB_PATTERN
+    char                    rgb_pattern_state;
+#endif
 } DRI2WindowStateRec, *DRI2WindowStatePtr;
 
 typedef struct {