media: ov7251: Improve error logging when fwnode is not found

The ov7251 driver waits for the endpoint fwnode to show up in case this
fwnode is created by a bridge-driver.

It does this by returning -EPROBE_DEFER, but it does not use
dev_err_probe() so no reason for deferring gets registered.

After 30 seconds the kernel logs a warning that the probe is still
deferred, which looks like this:

[   33.952052] i2c i2c-INT347E:00: deferred probe pending: (reason unknown)

Use dev_err_probe() when returning -EPROBE_DEFER to register the probe
deferral reason changing the error to:

deferred probe pending: waiting for fwnode graph endpoint

Also update the comment to not refer to the no longer existing cio2-bridge
code.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/media/i2c/ov7251.c b/drivers/media/i2c/ov7251.c
index 3226888d77e9..31a42d81e970 100644
--- a/drivers/media/i2c/ov7251.c
+++ b/drivers/media/i2c/ov7251.c
@@ -1486,9 +1486,14 @@ static int ov7251_check_hwcfg(struct ov7251 *ov7251)
 	unsigned int i, j;
 	int ret;
 
+	/*
+	 * Sometimes the fwnode graph is initialized by the bridge driver
+	 * Bridge drivers doing this may also add GPIO mappings, wait for this.
+	 */
 	endpoint = fwnode_graph_get_next_endpoint(fwnode, NULL);
 	if (!endpoint)
-		return -EPROBE_DEFER; /* could be provided by cio2-bridge */
+		return dev_err_probe(ov7251->dev, -EPROBE_DEFER,
+				     "waiting for fwnode graph endpoint\n");
 
 	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &bus_cfg);
 	fwnode_handle_put(endpoint);