drm: rcar-du: Add probe deferral debug messages

Print a message when the HDMI I2C slave encoder can't be found to help
debugging probe deferral issues.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c b/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
index 065b3a1d613495ef0fb406e68dbc1630403d9062..461662d231e2724b782de2c73f5537dbe2fef052 100644 (file)
--- a/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_hdmienc.c
@@ -131,12 +131,19 @@ int rcar_du_hdmienc_init(struct rcar_du_device *rcdu,
 
        /* Locate the slave I2C device and driver. */
        i2c_slave = of_find_i2c_device_by_node(np);
-       if (!i2c_slave || !i2c_get_clientdata(i2c_slave))
+       if (!i2c_slave || !i2c_get_clientdata(i2c_slave)) {
+               dev_dbg(rcdu->dev,
+                       "can't get I2C slave for %s, deferring probe\n",
+                       of_node_full_name(np));
                return -EPROBE_DEFER;
+       }
 
        hdmienc->dev = &i2c_slave->dev;
 
        if (hdmienc->dev->driver == NULL) {
+               dev_dbg(rcdu->dev,
+                       "I2C slave %s not probed yet, deferring probe\n",
+                       dev_name(hdmienc->dev));
                ret = -EPROBE_DEFER;
                goto error;
        }