releases/4.8.17/mn88473-fix-chip-id-check-on-probe.patch

From d930b5b5bf122a61952cfebabb1e618682a2631a Mon Sep 17 00:00:00 2001
From: Antti Palosaari <crope@iki.fi>
Date: Wed, 30 Nov 2016 19:36:14 -0200
Subject: [media] mn88473: fix chip id check on probe

From: Antti Palosaari <crope@iki.fi>

commit d930b5b5bf122a61952cfebabb1e618682a2631a 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: 7908fad99a6c ("[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 |   24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

--- a/drivers/media/dvb-frontends/mn88473.c
+++ b/drivers/media/dvb-frontends/mn88473.c
@@ -485,18 +485,6 @@ static int mn88473_probe(struct i2c_clie
 		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_clie
 	}
 	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)