diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 4dc5b4714c5a..39fa75bf7c4f 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -748,6 +748,8 @@ void evergreen_pcie_gart_tlb_flush(struct radeon_device *rdev)
 	unsigned i;
 	u32 tmp;
 
+	WREG32(HDP_MEM_COHERENCY_FLUSH_CNTL, 0x1);
+
 	WREG32(VM_CONTEXT0_REQUEST_RESPONSE, REQUEST_TYPE(1));
 	for (i = 0; i < rdev->usec_timeout; i++) {
 		/* read MC_STATUS */
diff --git a/drivers/gpu/drm/radeon/evergreend.h b/drivers/gpu/drm/radeon/evergreend.h
index 113c70cc8b39..a73b53c44359 100644
--- a/drivers/gpu/drm/radeon/evergreend.h
+++ b/drivers/gpu/drm/radeon/evergreend.h
@@ -174,6 +174,7 @@
 #define	HDP_NONSURFACE_BASE				0x2C04
 #define	HDP_NONSURFACE_INFO				0x2C08
 #define	HDP_NONSURFACE_SIZE				0x2C0C
+#define HDP_MEM_COHERENCY_FLUSH_CNTL			0x5480
 #define HDP_REG_COHERENCY_FLUSH_CNTL			0x54A0
 #define	HDP_TILING_CONFIG				0x2F3C