[linux-dvb] Preliminary support of Hauppauge Nova-T 500 Dual(take2)

hermann pitton hermann-pitton at arcor.de
Wed Sep 20 01:59:32 CEST 2006


Am Dienstag, den 19.09.2006, 16:51 -0400 schrieb Steven Toth:
> >> In the windows driver we leave the LNA off at all times, but have a registry
> >> override to allow users to enable it. It's a single LNA for both tuners -
> >> hence, it has its problems.
> >>
> >> Switching the LNA dynamically in a TV app isn't something the API allows. How
> >> about a module load param?
> >>     
> >
> > As updating an LNA (or something else) is very board specific, I put 
> > callback "update_lna" in dib3000mc_config. I will call this after starting 
> > the AGCs to see if the LNA has to be turned on or not (taking the agc 
> > response into account). For that I would like to know, what is the gain of 
> > the LNA when turned on? (So that I can adjust the thresholds when to turn 
> > on or off). Maybe we need to make an average of both channels, not that we 
> > kill one channel by only taking the other one into account. 
> >
> > Or is a module_parameter enough? (I don't like this, because the majority 
> > of users does not even now what is a module, which is good).
> >   
> Image a user that lives somewhere between two broadcast towers. They 
> receive some muxes at fairly weak levels and some very strong 
> (environment depending). We never found a good automatic solution to 
> deal with that within the (windows) driver.
> If the driver can be made to work reliably for all users in Linux under 
> all circumstances then that's ideal. :)
> Otherwise, the user may need some way to dictate LNA behavior.

looks like it is all because we are poor hackers ;)

With reliable data sheets signal strength and/or ber rates should
indicate when to switch.

Looks similar like the situation on analog radio. Guess _nobody_ knows
how to read auxiliary bits and recently a little more for all tuners
around to get at least stereo/signal strength ...


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