[linux-dvb] Re: Frontend experimental patch v1

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

On Saturday 06 March 2004 13:55, Oliver Endriss wrote:
> Hi,
>
> now I tried your patch with my DVB-S (BSRU6, stv01299-based).
> I'm using DiSEqC.
>
> Basically it seems to work fine, never encountered a zigzag scan. :)
> Tuning is somewhat slower, compared to my old reference driver
> (CVS DVB from November, with zigzag scan removed).
>
> Until now, I found that FE_SET_PARAMETERS is always called twice,
> with fe->state==2 and fe->state==4. Is this intentional?

Yeah, thats the frontend-core auto inversion. The stv0299 hardware doesn't 
support auto inversion by itself.

> BTW, does someone know why the stv0299 FE_SET_FRONTEND code
> does
>   /* A "normal" tune is requested */
>   stv0299_writereg (i2c, 0x32, 0x80);
>   stv0299_writereg (i2c, 0x22, 0x00);
>   stv0299_writereg (i2c, 0x23, 0x00);
>   stv0299_writereg (i2c, 0x32, 0x19);
>   stv0299_set_symbolrate (i2c, p->u.qpsk.symbol_rate, state->tuner_type);
>   stv0299_set_FEC (i2c, p->u.qpsk.fec_inner);
>   pll_set_tv_freq (i2c, p->frequency, state->tuner_type,
> p->u.qpsk.symbol_rate); * dvb_delay(50);
> * stv0299_writereg (i2c, 0x22, 0x00);
> * stv0299_writereg (i2c, 0x23, 0x00);
> * pll_set_tv_freq (i2c, p->frequency, state->tuner_type,
> p->u.qpsk.symbol_rate);
>
> The code looks somewhat strange to me. I don't understand why
> pll_set_tv_freq should be be called twice. I disabled the lines marked with
> * and tuning was faster.

That code from when I was still debugging what was going wrong with the 
stv0299; I thought it was necessary for a reliable lock, but it isn't. Thanks 
for reminding me; I meant to remove that.


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