@@ -1988,6 +1988,28 @@ static int tegra_dc_init(struct host1x_client *client)
struct drm_plane *cursor = NULL;
int err;
+ /*
+ * XXX do not register DCs with no window groups because we cannot
+ * assign a primary plane to them, which in turn will cause KMS to
+ * crash.
+ */
+ if (dc->soc->wgrps) {
+ bool has_wgrps = false;
+ unsigned int i;
+
+ for (i = 0; i < dc->soc->num_wgrps; i++) {
+ const struct tegra_windowgroup_soc *wgrp = &dc->soc->wgrps[i];
+
+ if (wgrp->dc == dc->pipe && wgrp->num_windows > 0) {
+ has_wgrps = true;
+ break;
+ }
+ }
+
+ if (!has_wgrps)
+ return 0;
+ }
+
dc->syncpt = host1x_syncpt_request(client, flags);
if (!dc->syncpt)
dev_warn(dc->dev, "failed to allocate syncpoint\n");