In the media drivers, the v4l2 core knows about all submodules
and calls into them from a common function. However this cannot
work if the modules that get called are loadable and the
core is built-in. In that case we get

drivers/built-in.o: In function `set_type':
drivers/media/v4l2-core/tuner-core.c:301: undefined reference to `tea5767_attach'
drivers/media/v4l2-core/tuner-core.c:307: undefined reference to `tea5761_attach'
drivers/media/v4l2-core/tuner-core.c:349: undefined reference to `tda9887_attach'
drivers/media/v4l2-core/tuner-core.c:405: undefined reference to `xc4000_attach'

This was working previously, until the IS_ENABLED() macro was used
to replace the construct like

 #if defined(CONFIG_DVB_CX24110) || (defined(CONFIG_DVB_CX24110_MODULE) && defined(MODULE))

with the difference that the new code no longer checks whether it is being
built as a loadable module itself.

To fix this, this new patch adds an 'IS_REACHABLE' macro, which evaluates
true in exactly the condition that was used previously. The downside
of this is that this trades an obvious link error for a more subtle
runtime failure, but it is clear that the change that introduced the
link error was unintentional and it seems better to revert it for
now. Also, a similar change was originally created by Trent Piepho
and then reverted by teh change to the IS_ENABLED macro.

Ideally Kconfig would be used to avoid the case of a broken dependency,
or the code restructured in a way to turn around the dependency, but either
way would require much larger changes here.

Fixes: 7b34be71 ("[media] use IS_ENABLED() macro")
See-also: c5dec9fb ("V4L/DVB (4751): Fix DBV_FE_CUSTOMISE for card drivers compiled into kernel")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

1) This is not allowed by the kernel coding style
2) Just configure your editor correctly
3) It's really ugly
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Acked-by: NSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

This patch introduces the use of IS_ENABLED() macro. For example,
replacing:
 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
with:
 #if IS_ENABLED(CONFIG_I2C)
All changes made by this patch respect the same replacement pattern.
Reported-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Acked-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Move the tuners one level up, as the "common" directory will be used
by drivers that are shared between more than one driver.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

mxl5007 was forcing for its compilation:

In file included from drivers/media/common/tuners/mxl5007t.c:25:drivers/media/common/tuners/mxl5007t.h:80:1: warning: "CONFIG_MEDIA_TUNER_MXL5007T" redefined
In file included from <command-line>:0:
./include/linux/autoconf.h:2782:1: warning: this is the location of the previous definition

Probably, some temporary hack for testing.

Cc: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Signed-off-by: NMichael Krufky <mkrufky@linuxtv.org>
Signed-off-by: NAsaf Fishov <afishov@maxlinear.com>
Signed-off-by: NCharles Kim <ckim@maxlinear.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>