drm/nouveau/gr: disable fifo access and idle before suspend ctx unload

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nv04_graph.c

@@ -540,6 +540,11 @@ nv04_graph_init(struct drm_device *dev, int engine)
 static int
 nv04_graph_fini(struct drm_device *dev, int engine, bool suspend)
 {
+	nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000000);
+	if (!nv_wait(dev, NV04_PGRAPH_STATUS, ~0, 0) && suspend) {
+		nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000001);
+		return -EBUSY;
+	}
 	nv04_graph_unload_context(dev);
 	nv_wr32(dev, NV03_PGRAPH_INTR_EN, 0x00000000);
 	return 0;

drivers/gpu/drm/nouveau/nv10_graph.c

@@ -959,6 +959,11 @@ nv10_graph_init(struct drm_device *dev, int engine)
 static int
 nv10_graph_fini(struct drm_device *dev, int engine, bool suspend)
 {
+	nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000000);
+	if (!nv_wait(dev, NV04_PGRAPH_STATUS, ~0, 0) && suspend) {
+		nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000001);
+		return -EBUSY;
+	}
 	nv10_graph_unload_context(dev);
 	nv_wr32(dev, NV03_PGRAPH_INTR_EN, 0x00000000);
 	return 0;

drivers/gpu/drm/nouveau/nv20_graph.c

@@ -656,6 +656,11 @@ nv30_graph_init(struct drm_device *dev, int engine)
 int
 nv20_graph_fini(struct drm_device *dev, int engine, bool suspend)
 {
+	nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000000);
+	if (!nv_wait(dev, NV04_PGRAPH_STATUS, ~0, 0) && suspend) {
+		nv_mask(dev, NV04_PGRAPH_FIFO, 0x00000001, 0x00000001);
+		return -EBUSY;
+	}
 	nv20_graph_unload_context(dev);
 	nv_wr32(dev, NV03_PGRAPH_INTR_EN, 0x00000000);
 	return 0;

drivers/gpu/drm/nouveau/nv50_graph.c

@@ -256,6 +256,11 @@ nv50_graph_init(struct drm_device *dev, int engine)
 static int
 nv50_graph_fini(struct drm_device *dev, int engine, bool suspend)
 {
+	nv_mask(dev, 0x400500, 0x00010001, 0x00000000);
+	if (!nv_wait(dev, 0x400700, ~0, 0) && suspend) {
+		nv_mask(dev, 0x400500, 0x00010001, 0x00010001);
+		return -EBUSY;
+	}
 	nv50_graph_unload_context(dev);
 	nv_wr32(dev, 0x40013c, 0x00000000);
 	return 0;