> Mauro Carvalho Chehab wrote:
>> On Tue, 13 May 2008 00:03:02 -0400
>> "Michael Krufky" <mkrufky@linuxtv.org> wrote:
>>
>>
>>> On Mon, May 12, 2008 at 10:54 PM, Mauro Carvalho Chehab
>>> <mchehab@infradead.org> wrote:
>>>
>>>> On Sun, 11 May 2008 08:34:06 -0400
>>>> "Michael Krufky" <mkrufky@linuxtv.org> wrote:
>>>>
>>>> > On Sun, May 11, 2008 at 3:21 AM, Ingo Molnar <mingo@elte.hu> wrote:
>>>> > >
>>>> > > x86.git testing found the following build failure:
>>>> > >
>>>> > > drivers/built-in.o: In function `pvr2_dvb_feed_thread':
>>>> > > pvrusb2-dvb.c:(.text+0x127e78): undefined reference to
>>>> `dvb_dmx_swfilter'
>>>> > > drivers/built-in.o: In function `pvr2_dvb_adapter_exit':
>>>> > > pvrusb2-dvb.c:(.text+0x128357): undefined reference to
>>>> `dvb_net_release'
>>>> > > pvrusb2-dvb.c:(.text+0x12836f): undefined reference to
>>>> `dvb_dmxdev_release'
>>>> > > [...]
>>>> > >
>>>> > > with this config:
>>>> > >
>>>> > >
>>>>
http://redhat.com/~mingo/misc/config-Sun_May_11_07_06_35_CEST_2008.bad
>>>> > >
>>>> > > the reason for the missing symbols is this combination:
>>>> > >
>>>> > > CONFIG_VIDEO_PVRUSB2=y
>>>> > > CONFIG_DVB_CORE=m
>>>> > >
>>>> > > i.e. pvrusb2 is built-in, dvb-core is modular.
>>>> > >
>>>> > > This patch solves the problem by adding a dependency on
>>>> DVB_CORE - this
>>>> > > is used by other drivers such as au0828 as well. This way the
>>>> pvrusb2
>>>> > > driver can still be built, but if dvb-core is a module then it
>>>> will
>>>> > > correctly be a module as well and cannot be built-in.
>>>> > >
>>>> > > Signed-off-by: Ingo Molnar <mingo@elte.hu>
>>>> > > ---
>>>> > > drivers/media/video/pvrusb2/Kconfig | 2 +-
>>>> > > 1 file changed, 1 insertion(+), 1 deletion(-)
>>>> > >
>>>> > > Index: linux/drivers/media/video/pvrusb2/Kconfig
>>>> > >
>>>> ===================================================================
>>>> > > --- linux.orig/drivers/media/video/pvrusb2/Kconfig
>>>> > > +++ linux/drivers/media/video/pvrusb2/Kconfig
>>>> > > @@ -1,6 +1,6 @@
>>>> > > config VIDEO_PVRUSB2
>>>> > > tristate "Hauppauge WinTV-PVR USB2 support"
>>>> > > - depends on VIDEO_V4L2 && I2C
>>>> > > + depends on VIDEO_V4L2 && I2C && DVB_CORE
>>>> > > select FW_LOADER
>>>> > > select MEDIA_TUNER
>>>> > > select VIDEO_TVEEPROM
>>>> > >
>>>> >
>>>> > Ingo,
>>>> >
>>>> > VIDEO_PVRUSB2 should not depend on DVB_CORE unless
>>>> VIDEO_PVRUSB2_DVB
>>>> > is selected, which already depends on DVB_CORE.
>>>> >
>>>> > For example, if a user has VIDEO_PVRUSB2_DVB not selected, then
>>>> your
>>>> > patch would generate a false dependency on DVB_CORE.
>>>>
>>>> Maybe we can make pvrusb2 dependent of VIDEO_MEDIA. This is a
>>>> DVB_CORE ||
>>>> VIDEO_DEV. So, pvrusb should be 'm' in this case.
>>>>
>>> That sounds like it would be OK, although something like this would
>>> probably be better:
>>>
>>> config VIDEO_PVRUSB2
>>> tristate "Hauppauge WinTV-PVR USB2 support"
>>> - depends on VIDEO_V4L2 && I2C
>>> + depends on VIDEO_V4L2 && I2C && (DVB_CORE if VIDEO_PVRUSB2_DVB)
>>> select FW_LOADER
>>> select MEDIA_TUNER
>>> select VIDEO_TVEEPROM
>>>
>>
>> This doesn't look to be a good idea, since VIDEO_PVRUSB2_DVB depends on
>> VIDEO_PVRUSB2. So, you'll create a circular dependency. The syntax I've
>> proposed seems cleaner. Of course, it needs to be tested. IMO, all
>> hybrid
>> devices should be dependent of VIDEO_MEDIA. This will help to avoid
>> this kind
>> of issue.
>>
>>
>>> I don't know if that syntax works for "depends on" , but it does work
>>> for select.
>>>
>>> if "depends on FOO if BAR" doesnt work, would adding "select DVB_CORE
>>> if VIDEO_PVRUSB2_DVB" solve the problem?
>>>
>>
>> Also, this leads into a circular reference.
> Mauro,
>
> You're right -- I didn't consider the circular dependency.
>
> Your suggestion (depends on VIDEO_MEDIA) seems like the right way to go.
