[linux-dvb] cx18 or tveeprom - Missing dependency? [PATCH]

Brandon Jenkins bcjenkins at tvwhere.com
Tue Jun 17 20:33:39 CEST 2008

On Jun 17, 2008, at 1:39 PM, mkrufky at linuxtv.org wrote:

> Brandon Jenkins wrote:
>> On Jun 17, 2008, at 12:17 PM, mkrufky at linuxtv.org wrote:
>>> Brandon Jenkins wrote:
>>>> On Jun 17, 2008, at 11:24 AM, mkrufky at linuxtv.org wrote:
>>>>> Brandon Jenkins wrote:
>>>>>> On Jun 17, 2008, at 10:52 AM, mkrufky at linuxtv.org wrote:
>>>>>>> Brandon Jenkins wrote:
>>>>>>> Brandon,
>>>>>>> VIDEO_CX18 selects VIDEO_TUNER , but you chose the option,
>>>>>>> "MEDIA_TUNER_CUSTOMIZE" , which turns off the automatic tuner
>>>>>>> dependency
>>>>>>> selections.  Please note the description of this option:
>>>>>>> menuconfig MEDIA_TUNER_CUSTOMIZE
>>>>>>>     bool "Customize analog and hybrid tuner modules to build"
>>>>>>>     depends on MEDIA_TUNER
>>>>>>>     help
>>>>>>>       This allows the user to deselect tuner drivers unnecessary
>>>>>>>       for their hardware from the build. Use this option with  
>>>>>>> care
>>>>>>>       as deselecting tuner drivers which are in fact necessary  
>>>>>>> will
>>>>>>>       result in V4L/DVB devices which cannot be tuned due to
>>>>>>> lack of
>>>>>>>       driver support
>>>>>>>       If unsure say N.
>>>>>>> We allow users to disable certain modules if they think they  
>>>>>>> know
>>>>>>> better, and choose to compile out drivers that they don't  
>>>>>>> need.  You
>>>>>>> should not have disabled tuner-simple -- to play it safe, don't
>>>>>>> enable
>>>>>>> Regards,
>>>>>>> Mike
>>>>>> Mike,
>>>>>> Thank you. I understand the impact my choice makes in that  
>>>>>> matter.
>>>>>> However, all of the other modules required for cx18 to function  
>>>>>> are
>>>>>> marked in the lists as -M- indicating it is a required module/ 
>>>>>> module
>>>>>> dependency. I apologize for my ignorance of terminology, etc.,  
>>>>>> but it
>>>>>> would seem to me that "Simple tuner support" should automatically
>>>>>> have
>>>>>> the -M- as a required resource for the tuner to function  
>>>>>> correctly.
>>>>>> Thank you for your time in responding.
>>>>>> Brandon
>>>>> No -- You are misunderstanding -- The selection of the tuner.ko  
>>>>> i2c
>>>>> client module is forced as -M- , since it is selected as a  
>>>>> dependency.
>>>>> You then proceeded into a deeper layer of customization, and  
>>>>> enabled
>>>>> "MEDIA_TUNER_CUSTOMIZE" -- this option allows you to disable tuner
>>>>> modules that should have otherwise been autoselected for your
>>>>> hardware.
>>>>> I repeat -- this is an advanced customization option, and you have
>>>>> been
>>>>> so warned by its Kconfig description.
>>>>> I am pushing up a patch now that disables MEDIA_TUNER_CUSTOMIZE by
>>>>> default.
>>>>> -Mike
>>>> Mike,
>>>> That doesn't solve the problem. I believe the patch below, will.
>>>> Brandon
>>>> diff -r 50be11af3fdb linux/drivers/media/video/cx18/Kconfig
>>>> --- a/linux/drivers/media/video/cx18/Kconfig    Mon Jun 16 18:04:06
>>>> 2008 -0300
>>>> +++ b/linux/drivers/media/video/cx18/Kconfig    Tue Jun 17 12:02:03
>>>> 2008 -0400
>>>> @@ -12,6 +12,7 @@ config VIDEO_CX18
>>>>    select VIDEO_CS5345
>>>>    select DVB_S5H1409
>>>>    select MEDIA_TUNER_MXL5005S
>>>> +    select MEDIA_TUNER_SIMPLE
>>>>    ---help---
>>>>      This is a video4linux driver for Conexant cx23418 based
>>>>      PCI combo video recorder devices.
>>> Brandon,
>>> Thank you for this, but this patch will not be merged.  I  
>>> explained in
>>> the quoted email, above, that you have invoked a deeper layer of
>>> customization that allows us to disable tuner modules, regardless of
>>> your actual hardware.
>>> This option was designed for the sake of larger drivers, such as  
>>> cx88 or
>>> saa7134, who may use many different tuners depending on the actual  
>>> board
>>> present.  In the future, there may eventually be a cx18 board that  
>>> does
>>> not use tuner-simple.  This option allows users to disable tuner- 
>>> simple
>>> from building.  The default behavior is to automatically select the
>>> tuner driver needed for your hardware, but when you enable
>>> MEDIA_TUNER_CUSTOMIZE, this autoselection is turned off.  This is  
>>> the
>>> correct behavior.
>>> I repeat again that this Kconfig option provides a warning to the  
>>> user
>>> that this should be enabled at your own risk, only.
>>> "Use this option with care as deselecting tuner drivers which are in
>>> fact necessary will result in V4L/DVB devices which cannot be  
>>> tuned due
>>> to lack of driver support."
>>> Do not enable MEDIA_TUNER_CUSTOMIZE unless you know what you're  
>>> doing.
>>> End of story.
>>> -Mike
>> Mike,
>> I don't mean to continue this debate, but if you say this is working
>> as designed I will leave it alone and move on. All other tuner  
>> modules
>> (the max linear) which are required by the cx18 to function are still
>> indeed -M- in the menuconfig view. Once I added the patch above  
>> Simple
>> tuner also became -M- indicating it was required by a selected board.
>> If Simple tuner is required for the card to function, it should be
>> automatically selected as are all the other tuner modules the card
>> requires.
>> AFAIK - The only way to deselect a required tuner module is to
>> deselect the card it supports.
>> Your message seems more about the principle of customizing which
>> modules are built, while I am trying to save further troubleshooting
>> by requiring the modules for my particular card to be automatically
>> selected if someone selects the card. I see the two as separate  
>> items.
>> If it is not appropriate to use the select TUNER in the Kconfig, whay
>> is the MaxlLinear in there?
>> Brandon
> That is a bug -- thanks for pointing it out.
> Clone this tree and try again:
> http://linuxtv.org/hg/~mkrufky/fix
> -Mike

This is effectively the same as when we first started this discussion.  
But I can confirm that your last change works as designed and the  
change to disallow customization by default does not.

A change to the perl script ./v4l/scripts/make_kconfig.pl needs to be  
done to set the default to no on that entry. I don't know perl, so I  
can't help there.

All of this though brings us back to the same point I started out  
with. If Simple tuner is required, and if !DVB_FE_CUSTOMISE, then  
there really ought to be a "select MEDIA_TUNER_SIMPLE if ! 
DVB_FE_CUSTOMISE" in the file. I know what needs to be done for the  
card to function, my purpose in bringing this up was to help others.


More information about the linux-dvb mailing list