drm/nv10: Don't oops if the card wants to switch to a channel with no grctx.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nv10_graph.c b/drivers/gpu/drm/nouveau/nv10_graph.c
index b2f6a57..8e68c97 100644 (file)
--- a/drivers/gpu/drm/nouveau/nv10_graph.c
+++ b/drivers/gpu/drm/nouveau/nv10_graph.c
@@ -803,7 +803,7 @@ nv10_graph_context_switch(struct drm_device *dev)
        /* Load context for next channel */
        chid = (nv_rd32(dev, NV04_PGRAPH_TRAPPED_ADDR) >> 20) & 0x1f;
        chan = dev_priv->fifos[chid];
-       if (chan)
+       if (chan && chan->pgraph_ctx)
                nv10_graph_load_context(chan);
 
        pgraph->fifo_access(dev, true);