drm: imx: imx-hdmi: return defer if can't get ddc i2c adapter

drm driver may probe before the i2c bus, so the driver should
defer probing until it is available

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/drivers/gpu/drm/imx/imx-hdmi.c b/drivers/gpu/drm/imx/imx-hdmi.c
index 3f96a5e..3118dde 100644
--- a/drivers/gpu/drm/imx/imx-hdmi.c
+++ b/drivers/gpu/drm/imx/imx-hdmi.c
@@ -1611,10 +1611,12 @@
 	ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0);
 	if (ddc_node) {
 		hdmi->ddc = of_find_i2c_adapter_by_node(ddc_node);
-		if (!hdmi->ddc)
-			dev_dbg(hdmi->dev, "failed to read ddc node\n");
-
 		of_node_put(ddc_node);
+		if (!hdmi->ddc) {
+			dev_dbg(hdmi->dev, "failed to read ddc node\n");
+			return -EPROBE_DEFER;
+		}
+
 	} else {
 		dev_dbg(hdmi->dev, "no ddc property found\n");
 	}