-

diff --git a/tests/prime_crc.c b/tests/prime_crc.c
index dccfa3f..5357fe8 100644
--- a/tests/prime_crc.c
+++ b/tests/prime_crc.c
@@ -93,6 +93,21 @@ static void mess_with_coherency(char *ptr)
 //	close(dma_buf_fd);
 }
 
+static char *drm_mmap_framebuffer(struct igt_fb *fb)
+{
+	char *ptr = NULL;
+	struct drm_mode_map_dumb mmap_arg;
+
+	memset(&mmap_arg, 0, sizeof(mmap_arg));
+	mmap_arg.handle = fb->gem_handle;
+	igt_assert(drmIoctl(drm_fd, DRM_IOCTL_MODE_MAP_DUMB, &mmap_arg) == 0);
+
+	ptr = mmap(NULL, BO_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, drm_fd, mmap_arg.offset);
+	igt_assert(ptr != MAP_FAILED);
+
+	return ptr;
+}
+
 static char *dmabuf_mmap_framebuffer(struct igt_fb *fb)
 {
   int dma_buf_fd;
@@ -117,7 +132,8 @@ static void get_method_crc(uint64_t tiling, igt_crc_t *crc, bool mess)
 		      DRM_FORMAT_XRGB8888, tiling, &fb);
 
 	if (mess)
-		ptr = dmabuf_mmap_framebuffer(&fb);
+		ptr = drm_mmap_framebuffer(&fb);
+		//ptr = dmabuf_mmap_framebuffer(&fb);
 
 	rc = drmModeSetCrtc(drm_fd, ms.crtc_id, fb.fb_id, 0, 0,
 			    &ms.connector_id, 1, ms.mode);
@@ -146,7 +162,7 @@ static void draw_method_subtest(uint64_t tiling)
 	// XXX: IIUC if we mess up with the scanout device, through a dma-buf mmap'ed
 	// pointer, then both the reference crc and the messed up one should be equal
 	// because the latter wasn't flushed. That's the theory, but it's not what's
-	// happening.
+	// happening and the following is not passing.
 	igt_assert_crc_equal(&reference_crc, &crc);
 }