[linux-dvb] [patch] Add support for different tuning algorithms

Manu Abraham abraham.manu at gmail.com
Tue Nov 15 19:31:19 CET 2005


Felix Domke wrote:

>Manu Abraham wrote:
>  
>
>>Initially we thought it would be best to do it in userspace, but the
>>addition of ioctls to the API, made that thought a bit diminished ..
>>This is applicable for most of the frontends though ..
>>    
>>
>Hm, let's ask the other way around:
>
>What is the advantage of doing this in kernelspace?
>
>Can we:
> - guarantee that all frontends behave the same, so we had a real,
>device independent, API?
>  
>

More or less that's the idea. That was Andrew's proposal as well.
But utilize the Hardware specific features too.

> - define an API which covers all possibilities (input ranges, ...), so
>we don't need additional, private IOCTLs?
>  
>

That is one of the thoughts, that i had been discussing with Andrew, 
such that we don't use IOCTL's privately, but rather in a more generic way.

> - pass results in a good way to the userspace? For example, a blocking
>read of a "frontend parameter" structure which returns new found
>transponders? Is this flexible enough?
>  
>

I am not yet through with this. But the idea is to manintain 
compatibility as much as possible. But saying compatibility for devices 
which doesn't have those features doesn't make sense, but a common 
interface for all these specific devices in some way or the other. 
Eventhough this would be considered "experimental" for a while.

What i suggested to Andrew was that probably we can have a branch in CVS 
to do this experimental stuff.
This is not limited to the mb86a15 alone , but also to chips like the 
STV0299 and others as well. I think it might need a bit of experiments 
though, to get things straight. The current way i started up with is 
without all the algo's but a generic way of doing it for the moment. 
Maybe some suggestions would be helpful, i will get the code out as soon 
as it is almost done, so that i can get some feedback on this .. ?


Manu




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