V4L/DVB (11846): ir-kbd-i2c: Don't assume all IR receivers are supported

The code in ir_probe makes the dangerous assumption that all IR
receivers are supported by the driver. The new i2c model makes it
possible for bridge drivers to instantiate IR devices before they are
supported, therefore the ir-kbd-i2c drivers must be made more robust
to not spam the logs or even crash on unsupported IR devices. Simply,
the driver will not bind to the unsupported devices.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/ir-kbd-i2c.c

@@ -298,7 +298,7 @@ static void ir_work(struct work_struct *work)
 static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	IR_KEYTAB_TYPE *ir_codes = NULL;
-	const char *name;
+	const char *name = NULL;
 	int ir_type;
 	struct IR_i2c *ir;
 	struct input_dev *input_dev;
@@ -380,8 +380,7 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		ir_codes    = ir_codes_avermedia_cardbus;
 		break;
 	default:
-		/* shouldn't happen */
-		printk(DEVNAME ": Huh? unknown i2c address (0x%02x)?\n", addr);
+		dprintk(1, DEVNAME ": Unsupported i2c address 0x%02x\n", addr);
 		err = -ENODEV;
 		goto err_out_free;
 	}
@@ -396,6 +395,14 @@ static int ir_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		ir->get_key = init_data->get_key;
 	}
 
+	/* Make sure we are all setup before going on */
+	if (!name || !ir->get_key || !ir_codes) {
+		dprintk(1, DEVNAME ": Unsupported device at address 0x%02x\n",
+			addr);
+		err = -ENODEV;
+		goto err_out_free;
+	}
+
 	/* Sets name */
 	snprintf(ir->name, sizeof(ir->name), "i2c IR (%s)", name);
 	ir->ir_codes = ir_codes;