drm/nvc0/fifo: prevent CHAN_TABLE_ERROR:CHANNEL_PENDING on fifo fini

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

drivers/gpu/drm/nouveau/core/engine/fifo/nvc0.c

@@ -250,9 +250,17 @@ nvc0_fifo_chan_fini(struct nouveau_object *object, bool suspend)
 	struct nvc0_fifo_priv *priv = (void *)object->engine;
 	struct nvc0_fifo_chan *chan = (void *)object;
 	u32 chid = chan->base.chid;
+	u32 mask, engine;
 
 	nv_mask(priv, 0x003004 + (chid * 8), 0x00000001, 0x00000000);
 	nvc0_fifo_playlist_update(priv);
+	mask = nv_rd32(priv, 0x0025a4);
+	for (engine = 0; mask && engine < 16; engine++) {
+		if (!(mask & (1 << engine)))
+			continue;
+		nv_mask(priv, 0x0025a8 + (engine * 4), 0x00000000, 0x00000000);
+		mask &= ~(1 << engine);
+	}
 	nv_wr32(priv, 0x003000 + (chid * 8), 0x00000000);
 
 	return nouveau_fifo_channel_fini(&chan->base, suspend);