[media] tvp5150: make read operations atomic

Instead of using two I2C operations between write and read,
use just one i2c_transfer. That allows I2C mutexes to not
let any other I2C transfer between the two.

Reviewed-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Tested-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/i2c/tvp5150.c

@@ -58,21 +58,17 @@ static int tvp5150_read(struct v4l2_subdev *sd, unsigned char addr)
 	struct i2c_client *c = v4l2_get_subdevdata(sd);
 	unsigned char buffer[1];
 	int rc;
-
-	buffer[0] = addr;
-
-	rc = i2c_master_send(c, buffer, 1);
-	if (rc < 0) {
-		v4l2_err(sd, "i2c i/o error: rc == %d (should be 1)\n", rc);
-		return rc;
-	}
-
-	msleep(10);
-
-	rc = i2c_master_recv(c, buffer, 1);
-	if (rc < 0) {
-		v4l2_err(sd, "i2c i/o error: rc == %d (should be 1)\n", rc);
-		return rc;
+	struct i2c_msg msg[] = {
+		{ .addr = c->addr, .flags = 0,
+		  .buf = &addr, .len = 1 },
+		{ .addr = c->addr, .flags = I2C_M_RD,
+		  .buf = buffer, .len = 1 }
+	};
+
+	rc = i2c_transfer(c->adapter, msg, 2);
+	if (rc < 0 || rc != 2) {
+		v4l2_err(sd, "i2c i/o error: rc == %d (should be 2)\n", rc);
+		return rc < 0 ? rc : -EIO;
 	}
 
 	v4l2_dbg(2, debug, sd, "tvp5150: read 0x%02x = 0x%02x\n", addr, buffer[0]);