[linux-dvb] Re: backwards compatability -was- actual cvs broken?

Manu Abraham abraham.manu at gmail.com
Thu Nov 3 21:05:44 CET 2005


Philip Prindeville wrote:

> Manu Abraham wrote:
>
>> Edgar Toernig wrote:
>>
>>> It should be possible to create a dummy bttv driver that only
>>> supplies GPIO and I2C access.  This dummy driver could even be
>>> part of the dvb-bt878 driver.  (I may be wrong but wasn't the
>>> first version of the dvb-bt878 driver like that?)  But you
>>> have to find someone who's willing spends some hours of work
>>> to do that :-)  I wouldn't - it's unsatisfying to invest a
>>> lot of work just to "remove" functionality.
>>>
>>>  
>>>
>>
>> Yeah, i can understand your feelings. It is kind of very frustraing 
>> when working with a card than spans subsystems, especially when you 
>> have a layered module. I have been subjected to the extreme 
>> frustration a while back, that bttv in V4L used to get screwed up, 
>> resulting in breakages elsewhere. The clueless users will keep 
>> complaining that other modules are not functioning as expected. Well, 
>> this is really hard.
>>
>> Well, this is the disadvantage of not having code duplication.
>>
>> But the real aspect of it is, that if all modules were to have code 
>> duplication, imagine the sixe of the kernel, and maintainabilty issues.
>>
>> The adavantage of not having code duplication is that bugs can be 
>> easily identified out, as the code review does not happen for a 
>> particular hardware, but happens in a generic manner.
>>
>> The only way compatibility can be ensured is subsystems play nice to 
>> each other. A while back it was quite difficult to get dvb-kernel and 
>> CVS to play nice to each other. Anyhow that situation has improved a 
>> lot, and it is not as bad as it was earlier. Anyway, both aspects has 
>> their own merits and demerits.
>>
>> Manu
>
>
>
>
> What about putting the glue code into a pseudo-device module that both
> the V4L and DVB modules depend on?
>
Hello Philip,

Things are easier when said, than done.

What about, say send in some code implying what you mean to do. To 
kickstart, maybe you can try out with a single bridge driver. You can 
try for one card how it looks like, and if that looks good, then why 
shall we not ? Eventhough, I didn't follow what you meant. Any attempt 
to make things simpler would be beneficial to all.


Regards,
Manu





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