-

diff --git a/tests/kms_pwrite_crc.c b/tests/kms_pwrite_crc.c
index 05b9e38..419b46d 100644
--- a/tests/kms_pwrite_crc.c
+++ b/tests/kms_pwrite_crc.c
@@ -50,6 +50,20 @@ typedef struct {
 	uint32_t devid;
 } data_t;
 
+static char *dmabuf_mmap_framebuffer(int drm_fd, struct igt_fb *fb)
+{
+	int dma_buf_fd;
+	char *ptr = NULL;
+
+	dma_buf_fd = prime_handle_to_fd(drm_fd, fb->gem_handle);
+	igt_assert(errno == 0);
+
+	ptr = mmap(NULL, fb->size, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf_fd, 0);
+	igt_assert(ptr != MAP_FAILED);
+
+	return ptr;
+}
+
 static void test(data_t *data)
 {
 	igt_display_t *display = &data->display;
@@ -57,6 +71,7 @@ static void test(data_t *data)
 	struct igt_fb *fb = &data->fb[1];
 	drmModeModeInfo *mode;
 	cairo_t *cr;
+	char *ptr;
 	uint32_t caching;
 	void *buf;
 	igt_crc_t crc;
@@ -67,6 +82,8 @@ static void test(data_t *data)
 	igt_create_fb(data->drm_fd, mode->hdisplay, mode->vdisplay,
 		      DRM_FORMAT_XRGB8888, LOCAL_DRM_FORMAT_MOD_NONE, fb);
 
+	ptr = dmabuf_mmap_framebuffer(data->drm_fd, fb);
+
 	cr = igt_get_cairo_ctx(data->drm_fd, fb);
 	igt_paint_test_pattern(cr, fb->width, fb->height);
 	cairo_destroy(cr);
@@ -83,11 +100,11 @@ static void test(data_t *data)
 	caching = gem_get_caching(data->drm_fd, fb->gem_handle);
 	igt_assert(caching == I915_CACHING_NONE || caching == I915_CACHING_DISPLAY);
 
-	/* use pwrite to make the other fb all white too */
+	/* use dmabuf pointer to make the other fb all white too */
 	buf = malloc(fb->size);
 	igt_assert(buf != NULL);
 	memset(buf, 0xff, fb->size);
-	gem_write(data->drm_fd, fb->gem_handle, 0, buf, fb->size);
+	memcpy(ptr, buf, fb->size);
 	free(buf);
 
 	/* and flip to it */