[linux-dvb] Re: Adding ops to dvb_frontend_ops

[Holger Waechtler <holger@qanu.de>]

Patrick Boettcher wrote:

> Hi,
>
> One week ago I wrote a mail "pid filtering in frontend" to this list, but
> I got no answer, now I answer myself.
>
> Again, shortly the problem: dib*-frontend drivers have a light pid filter
> mechanism which can be reached via normal frontend registers. Due the
> bandwidth limit in USB it has to be used.
> To make the frontend more versatile, I put the filter-stuff now into the
> frontend.
>
> The question now, how does the usb driver (which manages the TS and demux
> stuff) can use the pid filter ?
>  
can't you set this up in the start_feed()/stop_feed() callbacks?

> With the struct dvb_frontend_ops introduced with FE_REFACTORING a solution
> would be to add the one or the other operation.
>  
The dibusb driver is just an example for devices where the classic RF 
frontend/demod and demux/decoder can't cleanly get seperated, so it 
doesn't makes much sense to try to seperate the drivers. Maybe making 
the frontend driver a library file and access it directly bypassing the 
dvb_frontend code is the most useful option, but I'm not sure about 
this. Any opinions?

> For the dibcom-frontends that would be activate/deactive a pid and
> (de)activate the FIFO. I know that these operations will be empty for the
> most frontend drivers, but at least the two I'm writing on
> (dib3000mb/dib3000mc) would take benefit from it.
>
> Is something like this possible? Or would the API change be to heavy?
>  
I would prefer to postpone a generic solution in the API as long this is 
not a widely used architecture -- special hooks in the API for a single 
chipset only are not really a good idea.

Holger