drm/virtio: Add the fence in resource_flush if present

If the framebuffer associated with the plane contains a fence, then
it is added to resource_flush and will be waited upon for a max of
50 msecs or until it is signalled by the Host.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210610232456.671905-4-vivek.kasireddy@intel.comSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/virtio/virtgpu_plane.c

@@ -129,6 +129,40 @@ static void virtio_gpu_update_dumb_bo(struct virtio_gpu_device *vgdev,
 					   objs, NULL);
 }
 
+static void virtio_gpu_resource_flush(struct drm_plane *plane,
+				      uint32_t x, uint32_t y,
+				      uint32_t width, uint32_t height)
+{
+	struct drm_device *dev = plane->dev;
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct virtio_gpu_framebuffer *vgfb;
+	struct virtio_gpu_object *bo;
+
+	vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
+	bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
+	if (vgfb->fence) {
+		struct virtio_gpu_object_array *objs;
+
+		objs = virtio_gpu_array_alloc(1);
+		if (!objs)
+			return;
+		virtio_gpu_array_add_obj(objs, vgfb->base.obj[0]);
+		virtio_gpu_array_lock_resv(objs);
+		virtio_gpu_cmd_resource_flush(vgdev, bo->hw_res_handle, x, y,
+					      width, height, objs, vgfb->fence);
+		virtio_gpu_notify(vgdev);
+
+		dma_fence_wait_timeout(&vgfb->fence->f, true,
+				       msecs_to_jiffies(50));
+		dma_fence_put(&vgfb->fence->f);
+		vgfb->fence = NULL;
+	} else {
+		virtio_gpu_cmd_resource_flush(vgdev, bo->hw_res_handle, x, y,
+					      width, height, NULL, NULL);
+		virtio_gpu_notify(vgdev);
+	}
+}
+
 static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
 					    struct drm_atomic_state *state)
 {
@@ -198,12 +232,11 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
 		}
 	}
 
-	virtio_gpu_cmd_resource_flush(vgdev, bo->hw_res_handle,
-				      rect.x1,
-				      rect.y1,
-				      rect.x2 - rect.x1,
-				      rect.y2 - rect.y1);
-	virtio_gpu_notify(vgdev);
+	virtio_gpu_resource_flush(plane,
+				  rect.x1,
+				  rect.y1,
+				  rect.x2 - rect.x1,
+				  rect.y2 - rect.y1);
 }
 
 static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane,