V4L2-based build error

V4L2-based build error

[Jonathan Corbet]

If you configure V4L2 as a module, the config system will still let you
configure DVB_CORE built-in.  This yields:

  drivers/built-in.o: In function `v4l2_i2c_drv_attach_legacy':
  tuner-core.c:(.text+0x901d5): undefined reference to `v4l2_i2c_attach'
  drivers/built-in.o: In function `tuner_command':
  tuner-core.c:(.text+0x91aed): undefined reference to `v4l_printk_ioctl'

I never had trouble with this before 2.6.26-rc2.  I'm happy making
DVB_CORE modular, but it would be nice if the config system didn't allow
inconsistent setups.

jon

P.S. As I was digging into this, I ran into <media/v4l2-i2c-drv-legacy.h>, 
     which takes an interesting approach - function definitions and 
     module_init() within a header file?  This thing is included in a 
     number of places; it seems like there should be a better way...

Re: V4L2-based build error

[Mauro Carvalho Chehab]

Hi Jon,

On Mon, 12 May 2008 16:14:09 -0600
Jonathan Corbet <corbet@lwn.net> wrote:

> If you configure V4L2 as a module, the config system will still let you
> configure DVB_CORE built-in.  This yields:
> 
>   drivers/built-in.o: In function `v4l2_i2c_drv_attach_legacy':
>   tuner-core.c:(.text+0x901d5): undefined reference to `v4l2_i2c_attach'
>   drivers/built-in.o: In function `tuner_command':
>   tuner-core.c:(.text+0x91aed): undefined reference to `v4l_printk_ioctl'
> 
> I never had trouble with this before 2.6.26-rc2.  I'm happy making
> DVB_CORE modular, but it would be nice if the config system didn't allow
> inconsistent setups.

I have a number of patches meant to fix several troubles at v4l/dvb
compilation. I intend to send they soon for merging, but I want first to test
some random builds.


> P.S. As I was digging into this, I ran into <media/v4l2-i2c-drv-legacy.h>, 
>      which takes an interesting approach - function definitions and 
>      module_init() within a header file?  This thing is included in a 
>      number of places; it seems like there should be a better way...

This file is meant to be an interim approach to allow a smoothly change from
the old i2c probing way to the newer format. It should be there for some time,
until we can convert all v4l2 drivers to the new approach.


Cheers,
Mauro