media: em28xx: split up em28xx_dvb_init to reduce stack size
authorArnd Bergmann <arnd@arndb.de>
Mon, 11 Dec 2017 12:05:02 +0000 (07:05 -0500)
committerMauro Carvalho Chehab <mchehab@s-opensource.com>
Tue, 6 Mar 2018 09:59:57 +0000 (04:59 -0500)
With CONFIG_KASAN, the init function uses a large amount of kernel stack:

drivers/media/usb/em28xx/em28xx-dvb.c: In function 'em28xx_dvb_init.part.4':
drivers/media/usb/em28xx/em28xx-dvb.c:2061:1: error: the frame size of 3232 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]

Using gcc-7 with -fsanitize-address-use-after-scope makes this even worse:

drivers/media/usb/em28xx/em28xx-dvb.c: In function 'em28xx_dvb_init':
drivers/media/usb/em28xx/em28xx-dvb.c:2069:1: error: the frame size of 4280 bytes is larger than 3072 bytes [-Werror=frame-larger-than=]

By splitting out each part of the switch/case statement that has its own local
variables into a separate function, no single one of them uses more than 500 bytes,
and with a noinline_for_stack annotation we can ensure that they are not merged
back together.

[mchehab@s-opensource.com: fix conflict with changeset
 be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD second tuner functionality")]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
drivers/media/usb/em28xx/em28xx-dvb.c

index 9bc957690b459846cde82916cab054ea636cc753..ea921da43ea643c0e728356ce3934625b3ffa53f 100644 (file)
@@ -932,7 +932,7 @@ static struct lgdt3306a_config hauppauge_01595_lgdt3306a_config = {
 
 /* ------------------------------------------------------------------ */
 
-static int em28xx_attach_xc3028(u8 addr, struct em28xx *dev)
+static noinline_for_stack int em28xx_attach_xc3028(u8 addr, struct em28xx *dev)
 {
        struct dvb_frontend *fe;
        struct xc2028_config cfg;
@@ -1124,6 +1124,504 @@ static void em28xx_unregister_dvb(struct em28xx_dvb *dvb)
        dvb_unregister_adapter(&dvb->adapter);
 }
 
+static noinline_for_stack int em28174_dvb_init_pctv_460e(struct em28xx *dev)
+{
+       struct em28xx_dvb *dvb = dev->dvb;
+       struct i2c_client *client;
+       struct i2c_board_info board_info;
+       struct tda10071_platform_data tda10071_pdata = {};
+       struct a8293_platform_data a8293_pdata = {};
+       int result;
+
+       /* attach demod + tuner combo */
+       tda10071_pdata.clk = 40444000, /* 40.444 MHz */
+       tda10071_pdata.i2c_wr_max = 64,
+       tda10071_pdata.ts_mode = TDA10071_TS_SERIAL,
+       tda10071_pdata.pll_multiplier = 20,
+       tda10071_pdata.tuner_i2c_addr = 0x14,
+       memset(&board_info, 0, sizeof(board_info));
+       strlcpy(board_info.type, "tda10071_cx24118", I2C_NAME_SIZE);
+       board_info.addr = 0x55;
+       board_info.platform_data = &tda10071_pdata;
+       request_module("tda10071");
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
+       if (client == NULL || client->dev.driver == NULL) {
+               result = -ENODEV;
+               goto out_free;
+       }
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->fe[0] = tda10071_pdata.get_dvb_frontend(client);
+       dvb->i2c_client_demod = client;
+
+       /* attach SEC */
+       a8293_pdata.dvb_frontend = dvb->fe[0];
+       memset(&board_info, 0, sizeof(board_info));
+       strlcpy(board_info.type, "a8293", I2C_NAME_SIZE);
+       board_info.addr = 0x08;
+       board_info.platform_data = &a8293_pdata;
+       request_module("a8293");
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->i2c_client_sec = client;
+       result = 0;
+out_free:
+       return result;
+}
+
+static noinline_for_stack int em28178_dvb_init_pctv_461e(struct em28xx *dev)
+{
+       struct em28xx_dvb *dvb = dev->dvb;
+       struct i2c_client *client;
+       struct i2c_adapter *i2c_adapter;
+       struct i2c_board_info board_info;
+       struct m88ds3103_platform_data m88ds3103_pdata = {};
+       struct ts2020_config ts2020_config = {};
+       struct a8293_platform_data a8293_pdata = {};
+       int result;
+
+       /* attach demod */
+       m88ds3103_pdata.clk = 27000000;
+       m88ds3103_pdata.i2c_wr_max = 33;
+       m88ds3103_pdata.ts_mode = M88DS3103_TS_PARALLEL;
+       m88ds3103_pdata.ts_clk = 16000;
+       m88ds3103_pdata.ts_clk_pol = 1;
+       m88ds3103_pdata.agc = 0x99;
+       memset(&board_info, 0, sizeof(board_info));
+       strlcpy(board_info.type, "m88ds3103", I2C_NAME_SIZE);
+       board_info.addr = 0x68;
+       board_info.platform_data = &m88ds3103_pdata;
+       request_module("m88ds3103");
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
+       if (client == NULL || client->dev.driver == NULL) {
+               result = -ENODEV;
+               goto out_free;
+       }
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->fe[0] = m88ds3103_pdata.get_dvb_frontend(client);
+       i2c_adapter = m88ds3103_pdata.get_i2c_adapter(client);
+       dvb->i2c_client_demod = client;
+
+       /* attach tuner */
+       ts2020_config.fe = dvb->fe[0];
+       memset(&board_info, 0, sizeof(board_info));
+       strlcpy(board_info.type, "ts2022", I2C_NAME_SIZE);
+       board_info.addr = 0x60;
+       board_info.platform_data = &ts2020_config;
+       request_module("ts2020");
+       client = i2c_new_device(i2c_adapter, &board_info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->i2c_client_tuner = client;
+       /* delegate signal strength measurement to tuner */
+       dvb->fe[0]->ops.read_signal_strength =
+                       dvb->fe[0]->ops.tuner_ops.get_rf_strength;
+
+       /* attach SEC */
+       a8293_pdata.dvb_frontend = dvb->fe[0];
+       memset(&board_info, 0, sizeof(board_info));
+       strlcpy(board_info.type, "a8293", I2C_NAME_SIZE);
+       board_info.addr = 0x08;
+       board_info.platform_data = &a8293_pdata;
+       request_module("a8293");
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_tuner->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_tuner);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_tuner->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_tuner);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->i2c_client_sec = client;
+       result = 0;
+out_free:
+       return result;
+}
+
+static noinline_for_stack int em28178_dvb_init_pctv_292e(struct em28xx *dev)
+{
+       struct em28xx_dvb *dvb = dev->dvb;
+       struct i2c_adapter *adapter;
+       struct i2c_client *client;
+       struct i2c_board_info info;
+       struct si2168_config si2168_config;
+       struct si2157_config si2157_config;
+       int result;
+
+       /* attach demod */
+       memset(&si2168_config, 0, sizeof(si2168_config));
+       si2168_config.i2c_adapter = &adapter;
+       si2168_config.fe = &dvb->fe[0];
+       si2168_config.ts_mode = SI2168_TS_PARALLEL;
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "si2168", I2C_NAME_SIZE);
+       info.addr = 0x64;
+       info.platform_data = &si2168_config;
+       request_module(info.type);
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_demod = client;
+
+       /* attach tuner */
+       memset(&si2157_config, 0, sizeof(si2157_config));
+       si2157_config.fe = dvb->fe[0];
+       si2157_config.if_port = 1;
+#ifdef CONFIG_MEDIA_CONTROLLER_DVB
+       si2157_config.mdev = dev->media_dev;
+#endif
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "si2157", I2C_NAME_SIZE);
+       info.addr = 0x60;
+       info.platform_data = &si2157_config;
+       request_module(info.type);
+       client = i2c_new_device(adapter, &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_tuner = client;
+       dvb->fe[0]->ops.set_lna = em28xx_pctv_292e_set_lna;
+       result = 0;
+out_free:
+       return result;
+}
+
+static noinline_for_stack int em28178_dvb_init_terratec_t2_stick_hd(struct em28xx *dev)
+{
+       struct em28xx_dvb *dvb = dev->dvb;
+       struct i2c_adapter *adapter;
+       struct i2c_client *client;
+       struct i2c_board_info info;
+       struct si2168_config si2168_config;
+       struct si2157_config si2157_config;
+       int result;
+
+       /* attach demod */
+       memset(&si2168_config, 0, sizeof(si2168_config));
+       si2168_config.i2c_adapter = &adapter;
+       si2168_config.fe = &dvb->fe[0];
+       si2168_config.ts_mode = SI2168_TS_PARALLEL;
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "si2168", I2C_NAME_SIZE);
+       info.addr = 0x64;
+       info.platform_data = &si2168_config;
+       request_module(info.type);
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_demod = client;
+
+       /* attach tuner */
+       memset(&si2157_config, 0, sizeof(si2157_config));
+       si2157_config.fe = dvb->fe[0];
+       si2157_config.if_port = 0;
+#ifdef CONFIG_MEDIA_CONTROLLER_DVB
+       si2157_config.mdev = dev->media_dev;
+#endif
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "si2146", I2C_NAME_SIZE);
+       info.addr = 0x60;
+       info.platform_data = &si2157_config;
+       request_module("si2157");
+       client = i2c_new_device(adapter, &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_tuner = client;
+       result = 0;
+out_free:
+       return result;
+}
+
+static noinline_for_stack int em28178_dvb_init_plex_px_bcud(struct em28xx *dev)
+{
+       struct em28xx_dvb *dvb = dev->dvb;
+       struct i2c_client *client;
+       struct i2c_board_info info;
+       struct tc90522_config tc90522_config;
+       struct qm1d1c0042_config qm1d1c0042_config;
+       int result;
+
+       /* attach demod */
+       memset(&tc90522_config, 0, sizeof(tc90522_config));
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "tc90522sat", I2C_NAME_SIZE);
+       info.addr = 0x15;
+       info.platform_data = &tc90522_config;
+       request_module("tc90522");
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->i2c_client_demod = client;
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       /* attach tuner */
+       memset(&qm1d1c0042_config, 0,
+              sizeof(qm1d1c0042_config));
+       qm1d1c0042_config.fe = tc90522_config.fe;
+       qm1d1c0042_config.lpf = 1;
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "qm1d1c0042", I2C_NAME_SIZE);
+       info.addr = 0x61;
+       info.platform_data = &qm1d1c0042_config;
+       request_module(info.type);
+       client = i2c_new_device(tc90522_config.tuner_i2c,
+                               &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->i2c_client_tuner = client;
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       dvb->fe[0] = tc90522_config.fe;
+       px_bcud_init(dev);
+       result = 0;
+out_free:
+       return result;
+}
+
+static noinline_for_stack int em28174_dvb_init_hauppauge_wintv_dualhd_dvb(struct em28xx *dev)
+{
+       struct em28xx_dvb *dvb = dev->dvb;
+       struct i2c_adapter *adapter;
+       struct i2c_client *client;
+       struct i2c_board_info info;
+       struct si2168_config si2168_config;
+       struct si2157_config si2157_config;
+       int result;
+
+       /* attach demod */
+       memset(&si2168_config, 0, sizeof(si2168_config));
+       si2168_config.i2c_adapter = &adapter;
+       si2168_config.fe = &dvb->fe[0];
+       si2168_config.ts_mode = SI2168_TS_SERIAL;
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "si2168", I2C_NAME_SIZE);
+       if (dev->ts == PRIMARY_TS)
+               info.addr = 0x64;
+       else
+               info.addr = 0x67;
+       info.platform_data = &si2168_config;
+       request_module(info.type);
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_demod = client;
+
+       /* attach tuner */
+       memset(&si2157_config, 0, sizeof(si2157_config));
+       si2157_config.fe = dvb->fe[0];
+       si2157_config.if_port = 1;
+#ifdef CONFIG_MEDIA_CONTROLLER_DVB
+       si2157_config.mdev = dev->media_dev;
+#endif
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "si2157", I2C_NAME_SIZE);
+       if (dev->ts == PRIMARY_TS)
+               info.addr = 0x60;
+       else
+               info.addr = 0x63;
+       info.platform_data = &si2157_config;
+       request_module(info.type);
+       client = i2c_new_device(adapter, &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_tuner = client;
+       result = 0;
+out_free:
+       return result;
+}
+
+static int em28174_dvb_init_hauppauge_wintv_dualhd_01595(struct em28xx *dev)
+{
+       struct em28xx_dvb *dvb = dev->dvb;
+       struct i2c_adapter *adapter;
+       struct i2c_client *client;
+       struct i2c_board_info info = {};
+       struct lgdt3306a_config lgdt3306a_config;
+       struct si2157_config si2157_config = {};
+       int result;
+
+       /* attach demod */
+       lgdt3306a_config = hauppauge_01595_lgdt3306a_config;
+       lgdt3306a_config.fe = &dvb->fe[0];
+       lgdt3306a_config.i2c_adapter = &adapter;
+       strlcpy(info.type, "lgdt3306a", sizeof(info.type));
+       if (dev->ts == PRIMARY_TS)
+               info.addr = 0x59;
+       else
+               info.addr = 0x0e;
+       info.platform_data = &lgdt3306a_config;
+       request_module(info.type);
+       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus],
+                       &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_demod = client;
+
+       /* attach tuner */
+       si2157_config.fe = dvb->fe[0];
+       si2157_config.if_port = 1;
+       si2157_config.inversion = 1;
+#ifdef CONFIG_MEDIA_CONTROLLER_DVB
+       si2157_config.mdev = dev->media_dev;
+#endif
+       memset(&info, 0, sizeof(struct i2c_board_info));
+       strlcpy(info.type, "si2157", sizeof(info.type));
+       if (dev->ts == PRIMARY_TS)
+               info.addr = 0x60;
+       else
+               info.addr = 0x62;
+       info.platform_data = &si2157_config;
+       request_module(info.type);
+
+       client = i2c_new_device(adapter, &info);
+       if (client == NULL || client->dev.driver == NULL) {
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+       if (!try_module_get(client->dev.driver->owner)) {
+               i2c_unregister_device(client);
+               module_put(dvb->i2c_client_demod->dev.driver->owner);
+               i2c_unregister_device(dvb->i2c_client_demod);
+               result = -ENODEV;
+               goto out_free;
+       }
+
+       dvb->i2c_client_tuner = client;
+       result = 0;
+out_free:
+       return result;
+}
 static int em28xx_dvb_init(struct em28xx *dev)
 {
        int result = 0, dvb_alt = 0;
@@ -1426,60 +1924,11 @@ static int em28xx_dvb_init(struct em28xx *dev)
                                   &dev->i2c_adap[dev->def_i2c_bus],
                                   &c3tech_duo_tda18271_config);
                break;
-       case EM28174_BOARD_PCTV_460E: {
-               struct i2c_client *client;
-               struct i2c_board_info board_info;
-               struct tda10071_platform_data tda10071_pdata = {};
-               struct a8293_platform_data a8293_pdata = {};
-
-               /* attach demod + tuner combo */
-               tda10071_pdata.clk = 40444000, /* 40.444 MHz */
-               tda10071_pdata.i2c_wr_max = 64,
-               tda10071_pdata.ts_mode = TDA10071_TS_SERIAL,
-               tda10071_pdata.pll_multiplier = 20,
-               tda10071_pdata.tuner_i2c_addr = 0x14,
-               memset(&board_info, 0, sizeof(board_info));
-               strlcpy(board_info.type, "tda10071_cx24118", I2C_NAME_SIZE);
-               board_info.addr = 0x55;
-               board_info.platform_data = &tda10071_pdata;
-               request_module("tda10071");
-               client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
-               if (client == NULL || client->dev.driver == NULL) {
-                       result = -ENODEV;
+       case EM28174_BOARD_PCTV_460E:
+               result = em28174_dvb_init_pctv_460e(dev);
+               if (result)
                        goto out_free;
-               }
-               if (!try_module_get(client->dev.driver->owner)) {
-                       i2c_unregister_device(client);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               dvb->fe[0] = tda10071_pdata.get_dvb_frontend(client);
-               dvb->i2c_client_demod = client;
-
-               /* attach SEC */
-               a8293_pdata.dvb_frontend = dvb->fe[0];
-               memset(&board_info, 0, sizeof(board_info));
-               strlcpy(board_info.type, "a8293", I2C_NAME_SIZE);
-               board_info.addr = 0x08;
-               board_info.platform_data = &a8293_pdata;
-               request_module("a8293");
-               client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
-               if (client == NULL || client->dev.driver == NULL) {
-                       module_put(dvb->i2c_client_demod->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_demod);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               if (!try_module_get(client->dev.driver->owner)) {
-                       i2c_unregister_device(client);
-                       module_put(dvb->i2c_client_demod->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_demod);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               dvb->i2c_client_sec = client;
                break;
-       }
        case EM2874_BOARD_DELOCK_61959:
        case EM2874_BOARD_MAXMEDIA_UB425_TC:
                /* attach demodulator */
@@ -1626,415 +2075,35 @@ static int em28xx_dvb_init(struct em28xx *dev)
                        }
                }
                break;
-       case EM28178_BOARD_PCTV_461E: {
-               struct i2c_client *client;
-               struct i2c_adapter *i2c_adapter;
-               struct i2c_board_info board_info;
-               struct m88ds3103_platform_data m88ds3103_pdata = {};
-               struct ts2020_config ts2020_config = {};
-               struct a8293_platform_data a8293_pdata = {};
-
-               /* attach demod */
-               m88ds3103_pdata.clk = 27000000;
-               m88ds3103_pdata.i2c_wr_max = 33;
-               m88ds3103_pdata.ts_mode = M88DS3103_TS_PARALLEL;
-               m88ds3103_pdata.ts_clk = 16000;
-               m88ds3103_pdata.ts_clk_pol = 1;
-               m88ds3103_pdata.agc = 0x99;
-               memset(&board_info, 0, sizeof(board_info));
-               strlcpy(board_info.type, "m88ds3103", I2C_NAME_SIZE);
-               board_info.addr = 0x68;
-               board_info.platform_data = &m88ds3103_pdata;
-               request_module("m88ds3103");
-               client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
-               if (client == NULL || client->dev.driver == NULL) {
-                       result = -ENODEV;
+       case EM28178_BOARD_PCTV_461E:
+               result = em28178_dvb_init_pctv_461e(dev);
+               if (result)
                        goto out_free;
-               }
-               if (!try_module_get(client->dev.driver->owner)) {
-                       i2c_unregister_device(client);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               dvb->fe[0] = m88ds3103_pdata.get_dvb_frontend(client);
-               i2c_adapter = m88ds3103_pdata.get_i2c_adapter(client);
-               dvb->i2c_client_demod = client;
-
-               /* attach tuner */
-               ts2020_config.fe = dvb->fe[0];
-               memset(&board_info, 0, sizeof(board_info));
-               strlcpy(board_info.type, "ts2022", I2C_NAME_SIZE);
-               board_info.addr = 0x60;
-               board_info.platform_data = &ts2020_config;
-               request_module("ts2020");
-               client = i2c_new_device(i2c_adapter, &board_info);
-               if (client == NULL || client->dev.driver == NULL) {
-                       module_put(dvb->i2c_client_demod->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_demod);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               if (!try_module_get(client->dev.driver->owner)) {
-                       i2c_unregister_device(client);
-                       module_put(dvb->i2c_client_demod->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_demod);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               dvb->i2c_client_tuner = client;
-               /* delegate signal strength measurement to tuner */
-               dvb->fe[0]->ops.read_signal_strength =
-                               dvb->fe[0]->ops.tuner_ops.get_rf_strength;
-
-               /* attach SEC */
-               a8293_pdata.dvb_frontend = dvb->fe[0];
-               memset(&board_info, 0, sizeof(board_info));
-               strlcpy(board_info.type, "a8293", I2C_NAME_SIZE);
-               board_info.addr = 0x08;
-               board_info.platform_data = &a8293_pdata;
-               request_module("a8293");
-               client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &board_info);
-               if (client == NULL || client->dev.driver == NULL) {
-                       module_put(dvb->i2c_client_tuner->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_tuner);
-                       module_put(dvb->i2c_client_demod->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_demod);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               if (!try_module_get(client->dev.driver->owner)) {
-                       i2c_unregister_device(client);
-                       module_put(dvb->i2c_client_tuner->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_tuner);
-                       module_put(dvb->i2c_client_demod->dev.driver->owner);
-                       i2c_unregister_device(dvb->i2c_client_demod);
-                       result = -ENODEV;
-                       goto out_free;
-               }
-               dvb->i2c_client_sec = client;
                break;
-       }
        case EM28178_BOARD_PCTV_292E:
-               {
-                       struct i2c_adapter *adapter;
-                       struct i2c_client *client;
-                       struct i2c_board_info info;
-                       struct si2168_config si2168_config;
-                       struct si2157_config si2157_config;
-
-                       /* attach demod */
-                       memset(&si2168_config, 0, sizeof(si2168_config));
-                       si2168_config.i2c_adapter = &adapter;
-                       si2168_config.fe = &dvb->fe[0];
-                       si2168_config.ts_mode = SI2168_TS_PARALLEL;
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "si2168", I2C_NAME_SIZE);
-                       info.addr = 0x64;
-                       info.platform_data = &si2168_config;
-                       request_module(info.type);
-                       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_demod = client;
-
-                       /* attach tuner */
-                       memset(&si2157_config, 0, sizeof(si2157_config));
-                       si2157_config.fe = dvb->fe[0];
-                       si2157_config.if_port = 1;
-#ifdef CONFIG_MEDIA_CONTROLLER_DVB
-                       si2157_config.mdev = dev->media_dev;
-#endif
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "si2157", I2C_NAME_SIZE);
-                       info.addr = 0x60;
-                       info.platform_data = &si2157_config;
-                       request_module(info.type);
-                       client = i2c_new_device(adapter, &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_tuner = client;
-                       dvb->fe[0]->ops.set_lna = em28xx_pctv_292e_set_lna;
-               }
+               result = em28178_dvb_init_pctv_292e(dev);
+               if (result)
+                       goto out_free;
                break;
        case EM28178_BOARD_TERRATEC_T2_STICK_HD:
-               {
-                       struct i2c_adapter *adapter;
-                       struct i2c_client *client;
-                       struct i2c_board_info info;
-                       struct si2168_config si2168_config;
-                       struct si2157_config si2157_config;
-
-                       /* attach demod */
-                       memset(&si2168_config, 0, sizeof(si2168_config));
-                       si2168_config.i2c_adapter = &adapter;
-                       si2168_config.fe = &dvb->fe[0];
-                       si2168_config.ts_mode = SI2168_TS_PARALLEL;
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "si2168", I2C_NAME_SIZE);
-                       info.addr = 0x64;
-                       info.platform_data = &si2168_config;
-                       request_module(info.type);
-                       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_demod = client;
-
-                       /* attach tuner */
-                       memset(&si2157_config, 0, sizeof(si2157_config));
-                       si2157_config.fe = dvb->fe[0];
-                       si2157_config.if_port = 0;
-#ifdef CONFIG_MEDIA_CONTROLLER_DVB
-                       si2157_config.mdev = dev->media_dev;
-#endif
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "si2146", I2C_NAME_SIZE);
-                       info.addr = 0x60;
-                       info.platform_data = &si2157_config;
-                       request_module("si2157");
-                       client = i2c_new_device(adapter, &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_tuner = client;
-               }
+               result = em28178_dvb_init_terratec_t2_stick_hd(dev);
+               if (result)
+                       goto out_free;
                break;
-
        case EM28178_BOARD_PLEX_PX_BCUD:
-               {
-                       struct i2c_client *client;
-                       struct i2c_board_info info;
-                       struct tc90522_config tc90522_config;
-                       struct qm1d1c0042_config qm1d1c0042_config;
-
-                       /* attach demod */
-                       memset(&tc90522_config, 0, sizeof(tc90522_config));
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "tc90522sat", I2C_NAME_SIZE);
-                       info.addr = 0x15;
-                       info.platform_data = &tc90522_config;
-                       request_module("tc90522");
-                       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-                       dvb->i2c_client_demod = client;
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       /* attach tuner */
-                       memset(&qm1d1c0042_config, 0,
-                              sizeof(qm1d1c0042_config));
-                       qm1d1c0042_config.fe = tc90522_config.fe;
-                       qm1d1c0042_config.lpf = 1;
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "qm1d1c0042", I2C_NAME_SIZE);
-                       info.addr = 0x61;
-                       info.platform_data = &qm1d1c0042_config;
-                       request_module(info.type);
-                       client = i2c_new_device(tc90522_config.tuner_i2c,
-                                               &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-                       dvb->i2c_client_tuner = client;
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-                       dvb->fe[0] = tc90522_config.fe;
-                       px_bcud_init(dev);
-               }
+               result = em28178_dvb_init_plex_px_bcud(dev);
+               if (result)
+                       goto out_free;
                break;
        case EM28174_BOARD_HAUPPAUGE_WINTV_DUALHD_DVB:
-               {
-                       struct i2c_adapter *adapter;
-                       struct i2c_client *client;
-                       struct i2c_board_info info;
-                       struct si2168_config si2168_config;
-                       struct si2157_config si2157_config;
-
-                       /* attach demod */
-                       memset(&si2168_config, 0, sizeof(si2168_config));
-                       si2168_config.i2c_adapter = &adapter;
-                       si2168_config.fe = &dvb->fe[0];
-                       si2168_config.ts_mode = SI2168_TS_SERIAL;
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "si2168", I2C_NAME_SIZE);
-                       if (dev->ts == PRIMARY_TS)
-                               info.addr = 0x64;
-                       else
-                               info.addr = 0x67;
-                       info.platform_data = &si2168_config;
-                       request_module(info.type);
-                       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus], &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_demod = client;
-
-                       /* attach tuner */
-                       memset(&si2157_config, 0, sizeof(si2157_config));
-                       si2157_config.fe = dvb->fe[0];
-                       si2157_config.if_port = 1;
-#ifdef CONFIG_MEDIA_CONTROLLER_DVB
-                       si2157_config.mdev = dev->media_dev;
-#endif
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "si2157", I2C_NAME_SIZE);
-                       if (dev->ts == PRIMARY_TS)
-                               info.addr = 0x60;
-                       else
-                               info.addr = 0x63;
-                       info.platform_data = &si2157_config;
-                       request_module(info.type);
-                       client = i2c_new_device(adapter, &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_tuner = client;
-
-               }
+               result = em28174_dvb_init_hauppauge_wintv_dualhd_dvb(dev);
+               if (result)
+                       goto out_free;
                break;
        case EM28174_BOARD_HAUPPAUGE_WINTV_DUALHD_01595:
-               {
-                       struct i2c_adapter *adapter;
-                       struct i2c_client *client;
-                       struct i2c_board_info info = {};
-                       struct lgdt3306a_config lgdt3306a_config;
-                       struct si2157_config si2157_config = {};
-
-                       /* attach demod */
-                       lgdt3306a_config = hauppauge_01595_lgdt3306a_config;
-                       lgdt3306a_config.fe = &dvb->fe[0];
-                       lgdt3306a_config.i2c_adapter = &adapter;
-                       strlcpy(info.type, "lgdt3306a", sizeof(info.type));
-                       if (dev->ts == PRIMARY_TS)
-                               info.addr = 0x59;
-                       else
-                               info.addr = 0x0e;
-                       info.platform_data = &lgdt3306a_config;
-                       request_module(info.type);
-                       client = i2c_new_device(&dev->i2c_adap[dev->def_i2c_bus],
-                                       &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_demod = client;
-
-                       /* attach tuner */
-                       si2157_config.fe = dvb->fe[0];
-                       si2157_config.if_port = 1;
-                       si2157_config.inversion = 1;
-#ifdef CONFIG_MEDIA_CONTROLLER_DVB
-                       si2157_config.mdev = dev->media_dev;
-#endif
-                       memset(&info, 0, sizeof(struct i2c_board_info));
-                       strlcpy(info.type, "si2157", sizeof(info.type));
-                       if (dev->ts == PRIMARY_TS)
-                               info.addr = 0x60;
-                       else
-                               info.addr = 0x62;
-                       info.platform_data = &si2157_config;
-                       request_module(info.type);
-
-                       client = i2c_new_device(adapter, &info);
-                       if (client == NULL || client->dev.driver == NULL) {
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-                       if (!try_module_get(client->dev.driver->owner)) {
-                               i2c_unregister_device(client);
-                               module_put(dvb->i2c_client_demod->dev.driver->owner);
-                               i2c_unregister_device(dvb->i2c_client_demod);
-                               result = -ENODEV;
-                               goto out_free;
-                       }
-
-                       dvb->i2c_client_tuner = client;
-               }
+               result = em28174_dvb_init_hauppauge_wintv_dualhd_01595(dev);
+               if (result)
+                       goto out_free;
                break;
        default:
                dev_err(&dev->intf->dev,