mn88473: fix chip id check on probe

commit d930b5b5 upstream.

A register used to identify chip during probe was overwritten during
firmware download and due to that later probe's for warm chip were
failing. Detect chip from the another register, which is located on
different register bank 2.

Fixes: 7908fad9 ("[media] mn88473: finalize driver")
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/media/dvb-frontends/mn88473.c

@@ -485,18 +485,6 @@ static int mn88473_probe(struct i2c_client *client,
 		goto err_kfree;
 	}
 
-	/* Check demod answers with correct chip id */
-	ret = regmap_read(dev->regmap[0], 0xff, &uitmp);
-	if (ret)
-		goto err_regmap_0_regmap_exit;
-
-	dev_dbg(&client->dev, "chip id=%02x\n", uitmp);
-
-	if (uitmp != 0x03) {
-		ret = -ENODEV;
-		goto err_regmap_0_regmap_exit;
-	}
-
 	/*
 	 * Chip has three I2C addresses for different register banks. Used
 	 * addresses are 0x18, 0x1a and 0x1c. We register two dummy clients,
@@ -533,6 +521,18 @@ static int mn88473_probe(struct i2c_client *client,
 	}
 	i2c_set_clientdata(dev->client[2], dev);
 
+	/* Check demod answers with correct chip id */
+	ret = regmap_read(dev->regmap[2], 0xff, &uitmp);
+	if (ret)
+		goto err_regmap_2_regmap_exit;
+
+	dev_dbg(&client->dev, "chip id=%02x\n", uitmp);
+
+	if (uitmp != 0x03) {
+		ret = -ENODEV;
+		goto err_regmap_2_regmap_exit;
+	}
+
 	/* Sleep because chip is active by default */
 	ret = regmap_write(dev->regmap[2], 0x05, 0x3e);
 	if (ret)