[PATCH 2/2] [media] dvb-usb: avoid link error with dib3000m{b,c|

From: Arnd Bergmann
Date: Tue Jul 19 2016 - 11:17:27 EST

Tha ARM randconfig builds came up with another rare build failure
for the dib3000mc driver, when dvb-usb-dibusb-mb is built-in and
dib3000mc is a loadable module:

ERROR: "dibusb_dib3000mc_frontend_attach" [drivers/media/usb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!
ERROR: "dibusb_dib3000mc_tuner_attach" [drivers/media/usb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!

Apparently this used to be a valid configuration (build-time, not
run-time), but broke as part of a cleanup.

I tried reverting the cleanup, but saw that the code was still wrong
then. This version adds a dependency for dib3000mb, to ensure that
dib3000mb does not force the dibusb_dib3000mc_frontend_attach function
to be built-in when dib3000mc is a loadable module.

I have also checked the two other files that were changed in the original
cleanup, and found them to be correct in either version, so I do not
touch that part.

As this is a rather obscure bug, there is no need for backports.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Fixes: 028c70ff42783 ("[media] dvb-usb/dvb-usb-v2: use IS_ENABLED")
This is one of two different ways to avoid the link error, please
pick one of them. Adding a dependency is simpler but slighly
more limiting.
drivers/media/usb/dvb-usb/Kconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/media/usb/dvb-usb/Kconfig b/drivers/media/usb/dvb-usb/Kconfig
index 8c911119faa6..959fa09dfd92 100644
--- a/drivers/media/usb/dvb-usb/Kconfig
+++ b/drivers/media/usb/dvb-usb/Kconfig
@@ -44,6 +44,7 @@ config DVB_USB_DIBUSB_MB
depends on DVB_USB
select DVB_DIB3000MB
+ depends on DVB_DIB3000MC || !DVB_DIB3000MC
Support for USB 1.1 and 2.0 DVB-T receivers based on reference designs made by