[linux-dvb] Re: Couple of frontend questions

[Andrew de Quincey <adq_dvb@lidskialf.net>]

On Wednesday 25 February 2004 14:59, Johannes Stezenbach wrote:
> Johannes Stezenbach wrote:
> > Andrew de Quincey wrote:
> > > Why is there an FE_RESET ioctl immediately after the FE_SET_FRONTEND in
> > > dvb_frontend_recover.. surely the frontend code itself should take care
> > > of performing a reset if it needs to?
> >
> > FE_RESET does not reset the frontend, it just restarts the
> > signal acquisiton algorithms in the demodulator (not all demods
> > need you to do that manually). It should be renamed.
>
> Well, that's what I thought, but Holger explained to me that
> it does something different (see his mail).
>
> It seems the FE_CAN_RECOVER and FE_CAN_CLEAN_SETUP should be dropped,
> and some FE_NEEDS_A_KICK_IN_THE_ASS_TO_RECOVER and
> FE_HANGS_IF_WE_DO_NOT_TWIDDLE_SOME_BITS_AFTER_IT_REPORTS_SIGNAL_LOCK
> flags should be introduced. Very few frontends actually need these
> workarounds.

Hi, I've been looking about, and I have some alternative and perhaps clearer 
names for those bits.

FE_RESET seems to (currently) have two purposes: On some frontends, it is used 
immediately after tuning to kick off the tuning process. And it is only used 
then.

On the ves1x93 frontend, it is used for the purpose Holger describes; as a 
"thing" that needs to be done continually during tuning.

I would suggest the following is done:

FE_RESET ioctl. Change to FE_POLL. The frontends which use this only once to 
kick off tuning will be changed so that they just do this as part of 
FE_SET_FRONTEND, which is really how it should be anyway.

FE_CAN_CLEAN_SETUP. Remove this completely.

Add FE_NEEDS_POLL. If this is set, the FE_POLL internal ioctl will be issued 
during tuning. So only the ves1x93 frontend will currently have this set, and 
it will use it to reset the signal acquisition algorithms.

FE_CAN_RECOVER. Change name to FE_CAN_COMPENSATE_DRIFT. Same semantics as 
FE_CAN_RECOVER, but a clearer name.

What do you think? I won't actually do any of this until after you've done 
that release, to save you some hassle (sorry about checking the dvb_frontend 
changes in immediately BTW; I should have thought first).


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