media: af9013: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)

Locking the root adapter for __i2c_transfer will deadlock if the
device sits behind a mux-locked I2C mux. Switch to the finer-grained
i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not
sit behind a mux-locked mux, the two locking variants are equivalent.
Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/media/dvb-frontends/af9013.c

@@ -1312,10 +1312,10 @@ static int af9013_wregs(struct i2c_client *client, u8 cmd, u16 reg,
 	memcpy(&buf[3], val, len);
 
 	if (lock)
-		i2c_lock_adapter(client->adapter);
+		i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	ret = __i2c_transfer(client->adapter, msg, 1);
 	if (lock)
-		i2c_unlock_adapter(client->adapter);
+		i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	if (ret < 0) {
 		goto err;
 	} else if (ret != 1) {
@@ -1353,10 +1353,10 @@ static int af9013_rregs(struct i2c_client *client, u8 cmd, u16 reg,
 	buf[2] = cmd;
 
 	if (lock)
-		i2c_lock_adapter(client->adapter);
+		i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	ret = __i2c_transfer(client->adapter, msg, 2);
 	if (lock)
-		i2c_unlock_adapter(client->adapter);
+		i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	if (ret < 0) {
 		goto err;
 	} else if (ret != 2) {