diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index ddc3adea1dda..7a04959ba0ee 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -3528,7 +3528,8 @@ void r600_ioctl_wait_idle(struct radeon_device *rdev, struct radeon_bo *bo)
 	/* r7xx hw bug.  write to HDP_DEBUG1 followed by fb read
 	 * rather than write to HDP_REG_COHERENCY_FLUSH_CNTL
 	 */
-	if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740)) {
+	if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740) &&
+	    rdev->vram_scratch.ptr) {
 		void __iomem *ptr = (void *)rdev->vram_scratch.ptr;
 		u32 tmp;