[media] r820t: proper lock and set the I2C gate

As this tuner can be used by analog and digital parts of the
driver, be sure that all ops that access the hardware will
be be properly locked.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Antti Palosaari <crope@iki.fi>

drivers/media/tuners/r820t.c

@@ -1193,8 +1193,6 @@ static int generic_set_freq(struct dvb_frontend *fe,
 	tuner_dbg("should set frequency to %d kHz, bw %d MHz\n",
 		  freq / 1000, bw);
 
-	mutex_lock(&priv->lock);
-
 	if ((type == V4L2_TUNER_ANALOG_TV) && (std == V4L2_STD_SECAM_LC))
 		lo_freq = freq - priv->int_freq;
 	 else
@@ -1218,7 +1216,6 @@ static int generic_set_freq(struct dvb_frontend *fe,
 
 	rc = r820t_sysfreq_sel(priv, freq, type, std, delsys);
 err:
-	mutex_unlock(&priv->lock);
 
 	if (rc < 0)
 		tuner_dbg("%s: failed=%d\n", __func__, rc);
@@ -1335,6 +1332,8 @@ static int r820t_xtal_check(struct r820t_priv *priv)
 
 /*
  *  r820t frontend operations and tuner attach code
+ *
+ * All driver locks and i2c control are only in this part of the code
  */
 
 static int r820t_init(struct dvb_frontend *fe)
@@ -1345,11 +1344,10 @@ static int r820t_init(struct dvb_frontend *fe)
 
 	tuner_dbg("%s:\n", __func__);
 
+	mutex_lock(&priv->lock);
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1);
 
-	mutex_lock(&priv->lock);
-
 	if ((priv->cfg->rafael_chip == CHIP_R820T) ||
 	    (priv->cfg->rafael_chip == CHIP_R828S) ||
 	    (priv->cfg->rafael_chip == CHIP_R820C)) {
@@ -1369,17 +1367,13 @@ static int r820t_init(struct dvb_frontend *fe)
 	rc = r820t_write(priv, 0x05,
 			 r820t_init_array, sizeof(r820t_init_array));
 
-	mutex_unlock(&priv->lock);
-
-	if (fe->ops.i2c_gate_ctrl)
-		fe->ops.i2c_gate_ctrl(fe, 0);
-
-	return rc;
 err:
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
 
-	tuner_dbg("%s: failed=%d\n", __func__, rc);
+	if (rc < 0)
+		tuner_dbg("%s: failed=%d\n", __func__, rc);
 	return rc;
 }
 
@@ -1390,15 +1384,15 @@ static int r820t_sleep(struct dvb_frontend *fe)
 
 	tuner_dbg("%s:\n", __func__);
 
+	mutex_lock(&priv->lock);
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1);
 
-	mutex_lock(&priv->lock);
 	rc = r820t_standby(priv);
-	mutex_unlock(&priv->lock);
 
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
 
 	tuner_dbg("%s: failed=%d\n", __func__, rc);
 	return rc;
@@ -1409,6 +1403,7 @@ static int r820t_set_analog_freq(struct dvb_frontend *fe,
 {
 	struct r820t_priv *priv = fe->tuner_priv;
 	unsigned bw;
+	int rc;
 
 	tuner_dbg("%s called\n", __func__);
 
@@ -1421,8 +1416,18 @@ static int r820t_set_analog_freq(struct dvb_frontend *fe,
 	else
 		bw = 8;
 
-	return generic_set_freq(fe, 62500l * p->frequency, bw,
-				V4L2_TUNER_ANALOG_TV, p->std, SYS_UNDEFINED);
+	mutex_lock(&priv->lock);
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
+	rc = generic_set_freq(fe, 62500l * p->frequency, bw,
+			      V4L2_TUNER_ANALOG_TV, p->std, SYS_UNDEFINED);
+
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
+
+	return rc;
 }
 
 static int r820t_set_params(struct dvb_frontend *fe)
@@ -1435,6 +1440,7 @@ static int r820t_set_params(struct dvb_frontend *fe)
 	tuner_dbg("%s: delivery_system=%d frequency=%d bandwidth_hz=%d\n",
 		__func__, c->delivery_system, c->frequency, c->bandwidth_hz);
 
+	mutex_lock(&priv->lock);
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 1);
 
@@ -1447,6 +1453,7 @@ static int r820t_set_params(struct dvb_frontend *fe)
 
 	if (fe->ops.i2c_gate_ctrl)
 		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
 
 	if (rc)
 		tuner_dbg("%s: failed=%d\n", __func__, rc);
@@ -1458,10 +1465,14 @@ static int r820t_signal(struct dvb_frontend *fe, u16 *strength)
 	struct r820t_priv *priv = fe->tuner_priv;
 	int rc = 0;
 
+	mutex_lock(&priv->lock);
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
 	if (priv->has_lock) {
 		rc = r820t_read_gain(priv);
 		if (rc < 0)
-			return rc;
+			goto err;
 
 		/* A higher gain at LNA means a lower signal strength */
 		*strength = (45 - rc) << 4 | 0xff;
@@ -1469,6 +1480,11 @@ static int r820t_signal(struct dvb_frontend *fe, u16 *strength)
 		*strength = 0;
 	}
 
+err:
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
+
 	tuner_dbg("%s: %s, gain=%d strength=%d\n",
 		  __func__,
 		  priv->has_lock ? "PLL locked" : "no signal",