Re: videodev: Unknown symbol i2c_unregister_device (in kernels older than 2.6.26)

[Matt Doran <matt.doran@papercut.com>]

Andy Walls wrote:
> On Sun, 2009-05-24 at 20:52 -0400, David Ward wrote:
>   
>> On 05/24/2009 07:10 PM, Matt Doran wrote:
>>     
>>> Hi there,
>>>
>>> I tried using the latest v4l code on an Mythtv box running 2.6.20, but
>>> the v4l videodev module fails to load with the following warnings:
>>>
>>>    videodev: Unknown symbol i2c_unregister_device
>>>    v4l2_common: Unknown symbol v4l2_device_register_subdev
>>>
>>>
>>> It seems the "i2c_unregister_device" function was added in 2.6.26.
>>> References to this function in v4l2-common.c are enclosed in an ifdef
>>> like:
>>>
>>>    #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 26)
>>>
>>>
>>> However in "v4l2_device_unregister()" in v4l2-device.c, there is a
>>> reference to "i2c_unregister_device" without any ifdefs.   I am
>>> running a pretty old kernel, but I'd guess anyone running 2.6.25 or
>>> earlier will have this problem.   It seems this code was added by
>>> Mauro 3 weeks ago in this rev:
>>>
>>>    http://linuxtv.org/hg/v4l-dvb/rev/87afa7a4ccdf
>>>
>>>       
>> I have been seeing the errors compiling adv7343.c and ths7303.c under 
>> 2.6.24 as well.  Andy Walls and Chaithrika Subrahmanya had written 
>> patches for those two modules respectively, but there were some comments 
>> during the review of the patches, so I think they are still being worked on.
>>     
>
> Well, just to manage expectations: I am not working on this.  I do not
> advise waiting for something from me. ;)
>
>
> As an end user, you work-around is to use "make menuconfig" (or
> whatever) as Matt did: disable the modules that aren't compiling on
> older kernels.
>
>   
I agree, but the main problem I raise is the use of 
"i2c_unregister_device" in the main v4l module on Linux kernels that 
don't support it.

Regards,
Matt