media: cx231xx: Add second frontend option

Include ability to add a second dvb attach style frontend to cx231xx
USB bridge. All current boards set to use frontend[0]. Changes are
backwards compatible with current behaviour.

[mchehab@s-opensource.com: fix some coding style issues]
Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/cx231xx/cx231xx-dvb.c

@@ -55,7 +55,7 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
 #define CX231XX_DVB_MAX_PACKETS 64
 
 struct cx231xx_dvb {
-	struct dvb_frontend *frontend;
+	struct dvb_frontend *frontend[2];
 
 	/* feed count management */
 	struct mutex lock;
@@ -386,17 +386,17 @@ static int attach_xc5000(u8 addr, struct cx231xx *dev)
 	cfg.i2c_adap = cx231xx_get_i2c_adap(dev, dev->board.tuner_i2c_master);
 	cfg.i2c_addr = addr;
 
-	if (!dev->dvb->frontend) {
+	if (!dev->dvb->frontend[0]) {
 		dev_err(dev->dev, "%s/2: dvb frontend not attached. Can't attach xc5000\n",
 			dev->name);
 		return -EINVAL;
 	}
 
-	fe = dvb_attach(xc5000_attach, dev->dvb->frontend, &cfg);
+	fe = dvb_attach(xc5000_attach, dev->dvb->frontend[0], &cfg);
 	if (!fe) {
 		dev_err(dev->dev, "%s/2: xc5000 attach failed\n", dev->name);
-		dvb_frontend_detach(dev->dvb->frontend);
-		dev->dvb->frontend = NULL;
+		dvb_frontend_detach(dev->dvb->frontend[0]);
+		dev->dvb->frontend[0] = NULL;
 		return -EINVAL;
 	}
 
@@ -408,9 +408,9 @@ static int attach_xc5000(u8 addr, struct cx231xx *dev)
 
 int cx231xx_set_analog_freq(struct cx231xx *dev, u32 freq)
 {
-	if ((dev->dvb != NULL) && (dev->dvb->frontend != NULL)) {
+	if (dev->dvb && dev->dvb->frontend[0]) {
 
-		struct dvb_tuner_ops *dops = &dev->dvb->frontend->ops.tuner_ops;
+		struct dvb_tuner_ops *dops = &dev->dvb->frontend[0]->ops.tuner_ops;
 
 		if (dops->set_analog_params != NULL) {
 			struct analog_parameters params;
@@ -421,7 +421,7 @@ int cx231xx_set_analog_freq(struct cx231xx *dev, u32 freq)
 			/*params.audmode = ;       */
 
 			/* Set the analog parameters to set the frequency */
-			dops->set_analog_params(dev->dvb->frontend, &params);
+			dops->set_analog_params(dev->dvb->frontend[0], &params);
 		}
 
 	}
@@ -433,15 +433,15 @@ int cx231xx_reset_analog_tuner(struct cx231xx *dev)
 {
 	int status = 0;
 
-	if ((dev->dvb != NULL) && (dev->dvb->frontend != NULL)) {
+	if (dev->dvb && dev->dvb->frontend[0]) {
 
-		struct dvb_tuner_ops *dops = &dev->dvb->frontend->ops.tuner_ops;
+		struct dvb_tuner_ops *dops = &dev->dvb->frontend[0]->ops.tuner_ops;
 
 		if (dops->init != NULL && !dev->xc_fw_load_done) {
 
 			dev_dbg(dev->dev,
 				"Reloading firmware for XC5000\n");
-			status = dops->init(dev->dvb->frontend);
+			status = dops->init(dev->dvb->frontend[0]);
 			if (status == 0) {
 				dev->xc_fw_load_done = 1;
 				dev_dbg(dev->dev,
@@ -481,17 +481,29 @@ static int register_dvb(struct cx231xx_dvb *dvb,
 	dvb_register_media_controller(&dvb->adapter, dev->media_dev);
 
 	/* Ensure all frontends negotiate bus access */
-	dvb->frontend->ops.ts_bus_ctrl = cx231xx_dvb_bus_ctrl;
+	dvb->frontend[0]->ops.ts_bus_ctrl = cx231xx_dvb_bus_ctrl;
+	if (dvb->frontend[1])
+		dvb->frontend[1]->ops.ts_bus_ctrl = cx231xx_dvb_bus_ctrl;
 
 	dvb->adapter.priv = dev;
 
 	/* register frontend */
-	result = dvb_register_frontend(&dvb->adapter, dvb->frontend);
+	result = dvb_register_frontend(&dvb->adapter, dvb->frontend[0]);
 	if (result < 0) {
 		dev_warn(dev->dev,
 		       "%s: dvb_register_frontend failed (errno = %d)\n",
 		       dev->name, result);
-		goto fail_frontend;
+		goto fail_frontend0;
+	}
+
+	if (dvb->frontend[1]) {
+		result = dvb_register_frontend(&dvb->adapter, dvb->frontend[1]);
+		if (result < 0) {
+			dev_warn(dev->dev,
+				 "%s: 2nd dvb_register_frontend failed (errno = %d)\n",
+				dev->name, result);
+			goto fail_frontend1;
+		}
 	}
 
 	/* register demux stuff */
@@ -569,9 +581,14 @@ static int register_dvb(struct cx231xx_dvb *dvb,
 fail_dmxdev:
 	dvb_dmx_release(&dvb->demux);
 fail_dmx:
-	dvb_unregister_frontend(dvb->frontend);
-fail_frontend:
-	dvb_frontend_detach(dvb->frontend);
+	if (dvb->frontend[1])
+		dvb_unregister_frontend(dvb->frontend[1]);
+	dvb_unregister_frontend(dvb->frontend[0]);
+fail_frontend1:
+	if (dvb->frontend[1])
+		dvb_frontend_detach(dvb->frontend[1]);
+fail_frontend0:
+	dvb_frontend_detach(dvb->frontend[0]);
 	dvb_unregister_adapter(&dvb->adapter);
 fail_adapter:
 	return result;
@@ -585,8 +602,12 @@ static void unregister_dvb(struct cx231xx_dvb *dvb)
 	dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_hw);
 	dvb_dmxdev_release(&dvb->dmxdev);
 	dvb_dmx_release(&dvb->demux);
-	dvb_unregister_frontend(dvb->frontend);
-	dvb_frontend_detach(dvb->frontend);
+	if (dvb->frontend[1])
+		dvb_unregister_frontend(dvb->frontend[1]);
+	dvb_unregister_frontend(dvb->frontend[0]);
+	if (dvb->frontend[1])
+		dvb_frontend_detach(dvb->frontend[1]);
+	dvb_frontend_detach(dvb->frontend[0]);
 	dvb_unregister_adapter(&dvb->adapter);
 	/* remove I2C tuner */
 	client = dvb->i2c_client_tuner;
@@ -635,11 +656,11 @@ static int dvb_init(struct cx231xx *dev)
 	case CX231XX_BOARD_CNXT_CARRAERA:
 	case CX231XX_BOARD_CNXT_RDE_250:
 
-		dev->dvb->frontend = dvb_attach(s5h1432_attach,
+		dev->dvb->frontend[0] = dvb_attach(s5h1432_attach,
 					&dvico_s5h1432_config,
 					demod_i2c);
 
-		if (dev->dvb->frontend == NULL) {
+		if (!dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach s5h1432 front end\n");
 			result = -EINVAL;
@@ -647,9 +668,9 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
-		if (!dvb_attach(xc5000_attach, dev->dvb->frontend,
+		if (!dvb_attach(xc5000_attach, dev->dvb->frontend[0],
 			       tuner_i2c,
 			       &cnxt_rde250_tunerconfig)) {
 			result = -EINVAL;
@@ -660,11 +681,11 @@ static int dvb_init(struct cx231xx *dev)
 	case CX231XX_BOARD_CNXT_SHELBY:
 	case CX231XX_BOARD_CNXT_RDU_250:
 
-		dev->dvb->frontend = dvb_attach(s5h1411_attach,
+		dev->dvb->frontend[0] = dvb_attach(s5h1411_attach,
 					       &xc5000_s5h1411_config,
 					       demod_i2c);
 
-		if (dev->dvb->frontend == NULL) {
+		if (!dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach s5h1411 front end\n");
 			result = -EINVAL;
@@ -672,9 +693,9 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
-		if (!dvb_attach(xc5000_attach, dev->dvb->frontend,
+		if (!dvb_attach(xc5000_attach, dev->dvb->frontend[0],
 			       tuner_i2c,
 			       &cnxt_rdu250_tunerconfig)) {
 			result = -EINVAL;
@@ -683,11 +704,11 @@ static int dvb_init(struct cx231xx *dev)
 		break;
 	case CX231XX_BOARD_CNXT_RDE_253S:
 
-		dev->dvb->frontend = dvb_attach(s5h1432_attach,
+		dev->dvb->frontend[0] = dvb_attach(s5h1432_attach,
 					&dvico_s5h1432_config,
 					demod_i2c);
 
-		if (dev->dvb->frontend == NULL) {
+		if (!dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach s5h1432 front end\n");
 			result = -EINVAL;
@@ -695,9 +716,9 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
-		if (!dvb_attach(tda18271_attach, dev->dvb->frontend,
+		if (!dvb_attach(tda18271_attach, dev->dvb->frontend[0],
 			       0x60, tuner_i2c,
 			       &cnxt_rde253s_tunerconfig)) {
 			result = -EINVAL;
@@ -707,11 +728,11 @@ static int dvb_init(struct cx231xx *dev)
 	case CX231XX_BOARD_CNXT_RDU_253S:
 	case CX231XX_BOARD_KWORLD_UB445_USB_HYBRID:
 
-		dev->dvb->frontend = dvb_attach(s5h1411_attach,
+		dev->dvb->frontend[0] = dvb_attach(s5h1411_attach,
 					       &tda18271_s5h1411_config,
 					       demod_i2c);
 
-		if (dev->dvb->frontend == NULL) {
+		if (!dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach s5h1411 front end\n");
 			result = -EINVAL;
@@ -719,9 +740,9 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
-		if (!dvb_attach(tda18271_attach, dev->dvb->frontend,
+		if (!dvb_attach(tda18271_attach, dev->dvb->frontend[0],
 			       0x60, tuner_i2c,
 			       &cnxt_rde253s_tunerconfig)) {
 			result = -EINVAL;
@@ -734,11 +755,11 @@ static int dvb_init(struct cx231xx *dev)
 			 "%s: looking for tuner / demod on i2c bus: %d\n",
 		       __func__, i2c_adapter_id(tuner_i2c));
 
-		dev->dvb->frontend = dvb_attach(lgdt3305_attach,
+		dev->dvb->frontend[0] = dvb_attach(lgdt3305_attach,
 						&hcw_lgdt3305_config,
 						demod_i2c);
 
-		if (dev->dvb->frontend == NULL) {
+		if (!dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach LG3305 front end\n");
 			result = -EINVAL;
@@ -746,9 +767,9 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
-		dvb_attach(tda18271_attach, dev->dvb->frontend,
+		dvb_attach(tda18271_attach, dev->dvb->frontend[0],
 			   0x60, tuner_i2c,
 			   &hcw_tda18271_config);
 		break;
@@ -761,7 +782,7 @@ static int dvb_init(struct cx231xx *dev)
 
 		/* attach demod */
 		memset(&si2165_pdata, 0, sizeof(si2165_pdata));
-		si2165_pdata.fe = &dev->dvb->frontend;
+		si2165_pdata.fe = &dev->dvb->frontend[0];
 		si2165_pdata.chip_mode = SI2165_MODE_PLL_XTAL;
 		si2165_pdata.ref_freq_hz = 16000000;
 
@@ -771,7 +792,7 @@ static int dvb_init(struct cx231xx *dev)
 		info.platform_data = &si2165_pdata;
 		request_module(info.type);
 		client = i2c_new_device(demod_i2c, &info);
-		if (client == NULL || client->dev.driver == NULL || dev->dvb->frontend == NULL) {
+		if (!client || !client->dev.driver || !dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach SI2165 front end\n");
 			result = -EINVAL;
@@ -786,12 +807,12 @@ static int dvb_init(struct cx231xx *dev)
 
 		dvb->i2c_client_demod = client;
 
-		dev->dvb->frontend->ops.i2c_gate_ctrl = NULL;
+		dev->dvb->frontend[0]->ops.i2c_gate_ctrl = NULL;
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
-		dvb_attach(tda18271_attach, dev->dvb->frontend,
+		dvb_attach(tda18271_attach, dev->dvb->frontend[0],
 			0x60,
 			tuner_i2c,
 			&hcw_tda18271_config);
@@ -808,7 +829,7 @@ static int dvb_init(struct cx231xx *dev)
 
 		/* attach demod */
 		memset(&si2165_pdata, 0, sizeof(si2165_pdata));
-		si2165_pdata.fe = &dev->dvb->frontend;
+		si2165_pdata.fe = &dev->dvb->frontend[0];
 		si2165_pdata.chip_mode = SI2165_MODE_PLL_EXT;
 		si2165_pdata.ref_freq_hz = 24000000;
 
@@ -818,7 +839,7 @@ static int dvb_init(struct cx231xx *dev)
 		info.platform_data = &si2165_pdata;
 		request_module(info.type);
 		client = i2c_new_device(demod_i2c, &info);
-		if (client == NULL || client->dev.driver == NULL || dev->dvb->frontend == NULL) {
+		if (!client || !client->dev.driver || !dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach SI2165 front end\n");
 			result = -EINVAL;
@@ -835,14 +856,14 @@ static int dvb_init(struct cx231xx *dev)
 
 		memset(&info, 0, sizeof(struct i2c_board_info));
 
-		dev->dvb->frontend->ops.i2c_gate_ctrl = NULL;
+		dev->dvb->frontend[0]->ops.i2c_gate_ctrl = NULL;
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
 		/* attach tuner */
 		memset(&si2157_config, 0, sizeof(si2157_config));
-		si2157_config.fe = dev->dvb->frontend;
+		si2157_config.fe = dev->dvb->frontend[0];
 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
 		si2157_config.mdev = dev->media_dev;
 #endif
@@ -857,14 +878,14 @@ static int dvb_init(struct cx231xx *dev)
 			tuner_i2c,
 			&info);
 		if (client == NULL || client->dev.driver == NULL) {
-			dvb_frontend_detach(dev->dvb->frontend);
+			dvb_frontend_detach(dev->dvb->frontend[0]);
 			result = -ENODEV;
 			goto out_free;
 		}
 
 		if (!try_module_get(client->dev.driver->owner)) {
 			i2c_unregister_device(client);
-			dvb_frontend_detach(dev->dvb->frontend);
+			dvb_frontend_detach(dev->dvb->frontend[0]);
 			result = -ENODEV;
 			goto out_free;
 		}
@@ -882,26 +903,26 @@ static int dvb_init(struct cx231xx *dev)
 
 		memset(&info, 0, sizeof(struct i2c_board_info));
 
-		dev->dvb->frontend = dvb_attach(lgdt3306a_attach,
+		dev->dvb->frontend[0] = dvb_attach(lgdt3306a_attach,
 			&hauppauge_955q_lgdt3306a_config,
 			demod_i2c
 			);
 
-		if (dev->dvb->frontend == NULL) {
+		if (!dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach LGDT3306A frontend.\n");
 			result = -EINVAL;
 			goto out_free;
 		}
 
-		dev->dvb->frontend->ops.i2c_gate_ctrl = NULL;
+		dev->dvb->frontend[0]->ops.i2c_gate_ctrl = NULL;
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
 		/* attach tuner */
 		memset(&si2157_config, 0, sizeof(si2157_config));
-		si2157_config.fe = dev->dvb->frontend;
+		si2157_config.fe = dev->dvb->frontend[0];
 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
 		si2157_config.mdev = dev->media_dev;
 #endif
@@ -916,14 +937,14 @@ static int dvb_init(struct cx231xx *dev)
 			tuner_i2c,
 			&info);
 		if (client == NULL || client->dev.driver == NULL) {
-			dvb_frontend_detach(dev->dvb->frontend);
+			dvb_frontend_detach(dev->dvb->frontend[0]);
 			result = -ENODEV;
 			goto out_free;
 		}
 
 		if (!try_module_get(client->dev.driver->owner)) {
 			i2c_unregister_device(client);
-			dvb_frontend_detach(dev->dvb->frontend);
+			dvb_frontend_detach(dev->dvb->frontend[0]);
 			result = -ENODEV;
 			goto out_free;
 		}
@@ -940,11 +961,11 @@ static int dvb_init(struct cx231xx *dev)
 			 "%s: looking for demod on i2c bus: %d\n",
 			 __func__, i2c_adapter_id(tuner_i2c));
 
-		dev->dvb->frontend = dvb_attach(mb86a20s_attach,
+		dev->dvb->frontend[0] = dvb_attach(mb86a20s_attach,
 						&pv_mb86a20s_config,
 						demod_i2c);
 
-		if (dev->dvb->frontend == NULL) {
+		if (!dev->dvb->frontend[0]) {
 			dev_err(dev->dev,
 				"Failed to attach mb86a20s demod\n");
 			result = -EINVAL;
@@ -952,9 +973,9 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
-		dvb_attach(tda18271_attach, dev->dvb->frontend,
+		dvb_attach(tda18271_attach, dev->dvb->frontend[0],
 			   0x60, tuner_i2c,
 			   &pv_tda18271_config);
 		break;
@@ -969,7 +990,7 @@ static int dvb_init(struct cx231xx *dev)
 
 		/* attach demodulator chip */
 		si2168_config.ts_mode = SI2168_TS_SERIAL; /* from *.inf file */
-		si2168_config.fe = &dev->dvb->frontend;
+		si2168_config.fe = &dev->dvb->frontend[0];
 		si2168_config.i2c_adapter = &adapter;
 		si2168_config.ts_clock_inv = true;
 
@@ -994,7 +1015,7 @@ static int dvb_init(struct cx231xx *dev)
 		dvb->i2c_client_demod = client;
 
 		/* attach tuner chip */
-		si2157_config.fe = dev->dvb->frontend;
+		si2157_config.fe = dev->dvb->frontend[0];
 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
 		si2157_config.mdev = dev->media_dev;
 #endif
@@ -1037,7 +1058,7 @@ static int dvb_init(struct cx231xx *dev)
 		/* attach demodulator chip */
 		mn88473_config.i2c_wr_max = 16;
 		mn88473_config.xtal = 25000000;
-		mn88473_config.fe = &dev->dvb->frontend;
+		mn88473_config.fe = &dev->dvb->frontend[0];
 
 		strlcpy(info.type, "mn88473", sizeof(info.type));
 		info.addr = dev->board.demod_addr;
@@ -1060,10 +1081,10 @@ static int dvb_init(struct cx231xx *dev)
 		dvb->i2c_client_demod = client;
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
 		/* attach tuner chip */
-		dvb_attach(r820t_attach, dev->dvb->frontend,
+		dvb_attach(r820t_attach, dev->dvb->frontend[0],
 			   tuner_i2c,
 			   &astrometa_t2hybrid_r820t_config);
 		break;
@@ -1078,7 +1099,7 @@ static int dvb_init(struct cx231xx *dev)
 
 		/* attach demodulator chip */
 		si2168_config.ts_mode = SI2168_TS_SERIAL;
-		si2168_config.fe = &dev->dvb->frontend;
+		si2168_config.fe = &dev->dvb->frontend[0];
 		si2168_config.i2c_adapter = &adapter;
 		si2168_config.ts_clock_inv = true;
 
@@ -1102,13 +1123,13 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		dvb->i2c_client_demod = client;
-		dev->dvb->frontend->ops.i2c_gate_ctrl = NULL;
+		dev->dvb->frontend[0]->ops.i2c_gate_ctrl = NULL;
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
 		/* attach tuner */
-		si2157_config.fe = dev->dvb->frontend;
+		si2157_config.fe = dev->dvb->frontend[0];
 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
 		si2157_config.mdev = dev->media_dev;
 #endif
@@ -1153,7 +1174,7 @@ static int dvb_init(struct cx231xx *dev)
 
 		/* attach demodulator chip */
 		lgdt3306a_config = hauppauge_955q_lgdt3306a_config;
-		lgdt3306a_config.fe = &dev->dvb->frontend;
+		lgdt3306a_config.fe = &dev->dvb->frontend[0];
 		lgdt3306a_config.i2c_adapter = &adapter;
 
 		strlcpy(info.type, "lgdt3306a", sizeof(info.type));
@@ -1176,13 +1197,13 @@ static int dvb_init(struct cx231xx *dev)
 		}
 
 		dvb->i2c_client_demod = client;
-		dev->dvb->frontend->ops.i2c_gate_ctrl = NULL;
+		dev->dvb->frontend[0]->ops.i2c_gate_ctrl = NULL;
 
 		/* define general-purpose callback pointer */
-		dvb->frontend->callback = cx231xx_tuner_callback;
+		dvb->frontend[0]->callback = cx231xx_tuner_callback;
 
 		/* attach tuner */
-		si2157_config.fe = dev->dvb->frontend;
+		si2157_config.fe = dev->dvb->frontend[0];
 #ifdef CONFIG_MEDIA_CONTROLLER_DVB
 		si2157_config.mdev = dev->media_dev;
 #endif
@@ -1223,7 +1244,7 @@ static int dvb_init(struct cx231xx *dev)
 			dev->name);
 		break;
 	}
-	if (NULL == dvb->frontend) {
+	if (!dvb->frontend[0]) {
 		dev_err(dev->dev,
 		       "%s/2: frontend initialization failed\n", dev->name);
 		result = -EINVAL;