panel-raspberrypi-touchscreen: Fix NULL deref if probe order goes wrong.

If the i2c driver hadn't pobed before the panel driver probes, then
the client would be NULL but we were looking for an ERR_PTR in the
error case.

Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
index 7f315f04b109621ca7f3861fdd8acf956e752629..b57b7ad9aa4c5048186e98553af59ec912973096 100644 (file)
--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -404,6 +404,9 @@ static struct i2c_client *rpi_touchscreen_get_i2c(struct device *dev,
 
        of_node_put(node);
 
+       if (!client)
+               return ERR_PTR(-EPROBE_DEFER);
+
        return client;
 }