i2c: Warn on i2c client creation failure

i2c: Warn on i2c client creation failure

Warn when an i2c client creation fails. If we don't, the user will
never know something wrong happened, as i2c client creation is
typically called through an attach_adapter callback, those return value
we currently ignore for technical reasons.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/i2c/i2c-core.c

@@ -707,11 +707,16 @@ static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
 
 	/* Finally call the custom detection function */
 	err = found_proc(adapter, addr, kind);
-
 	/* -ENODEV can be returned if there is a chip at the given address
 	   but it isn't supported by this chip driver. We catch it here as
 	   this isn't an error. */
-	return (err == -ENODEV) ? 0 : err;
+	if (err == -ENODEV)
+		err = 0;
+
+	if (err)
+		dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n",
+			 addr, err);
+	return err;
 }
 
 int i2c_probe(struct i2c_adapter *adapter,