media: dib0700: fix link error for dibx000_i2c_set_speed

BugLink: https://bugs.launchpad.net/bugs/1847155
[ Upstream commit 765bb8610d305ee488b35d07e2a04ae52fb2df9c ]

When CONFIG_DVB_DIB9000 is disabled, we can still compile code that
now fails to link against dibx000_i2c_set_speed:

drivers/media/usb/dvb-usb/dib0700_devices.o: In function `dib01x0_pmu_update.constprop.7':
dib0700_devices.c:(.text.unlikely+0x1c9c): undefined reference to `dibx000_i2c_set_speed'

The call sites are both through dib01x0_pmu_update(), which gets passed
an 'i2c' pointer from dib9000_get_i2c_master(), which has returned
NULL. Checking this pointer seems to be a good idea anyway, and it avoids
the link failure in most cases.

Sean Young found another case that is not fixed by that, where certain
gcc versions leave an unused function in place that causes the link error,
but adding an explict IS_ENABLED() check also solves this.

Fixes: b7f54910ce01 ("V4L/DVB (4647): Added module for DiB0700 based devices")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/media/usb/dvb-usb/dib0700_devices.c b/drivers/media/usb/dvb-usb/dib0700_devices.c
index a9968fb1e8e4c8b28d962929e4f0124305d9c003..8185607ab970917e22eed722fbd73176c9b132df 100644 (file)
--- a/drivers/media/usb/dvb-usb/dib0700_devices.c
+++ b/drivers/media/usb/dvb-usb/dib0700_devices.c
@@ -2438,9 +2438,13 @@ static int dib9090_tuner_attach(struct dvb_usb_adapter *adap)
                8, 0x0486,
        };
 
+       if (!IS_ENABLED(CONFIG_DVB_DIB9000))
+               return -ENODEV;
        if (dvb_attach(dib0090_fw_register, adap->fe_adap[0].fe, i2c, &dib9090_dib0090_config) == NULL)
                return -ENODEV;
        i2c = dib9000_get_i2c_master(adap->fe_adap[0].fe, DIBX000_I2C_INTERFACE_GPIO_1_2, 0);
+       if (!i2c)
+               return -ENODEV;
        if (dib01x0_pmu_update(i2c, data_dib190, 10) != 0)
                return -ENODEV;
        dib0700_set_i2c_speed(adap->dev, 1500);
@@ -2516,10 +2520,14 @@ static int nim9090md_tuner_attach(struct dvb_usb_adapter *adap)
                0, 0x00ef,
                8, 0x0406,
        };
+       if (!IS_ENABLED(CONFIG_DVB_DIB9000))
+               return -ENODEV;
        i2c = dib9000_get_tuner_interface(adap->fe_adap[0].fe);
        if (dvb_attach(dib0090_fw_register, adap->fe_adap[0].fe, i2c, &nim9090md_dib0090_config[0]) == NULL)
                return -ENODEV;
        i2c = dib9000_get_i2c_master(adap->fe_adap[0].fe, DIBX000_I2C_INTERFACE_GPIO_1_2, 0);
+       if (!i2c)
+               return -ENODEV;
        if (dib01x0_pmu_update(i2c, data_dib190, 10) < 0)
                return -ENODEV;