On Wed, 2011-07-06 at 21:35 +0100, Malcolm Priestley wrote: > On Wed, 2011-07-06 at 13:34 +0200, Sébastien RAILLARD (COEXSI) wrote: > > > > > -----Original Message----- > > > From: Oliver Endriss [mailto:o.endriss@xxxxxx] > > > Sent: lundi 4 juillet 2011 00:43 > > > To: Linux Media Mailing List > > > Cc: Sébastien RAILLARD (COEXSI); Malcolm Priestley > > > Subject: Re: [DVB] TT S-1500b tuning issue > > > > > > On Wednesday 29 June 2011 15:16:10 Sébastien RAILLARD wrote: > > > > Dear all, > > > > > > > > We have found what seems to be a tuning issue in the driver for the > > > > ALPS BSBE1-D01A used in the new TT-S-1500b card from Technotrend. > > > > On some transponders, like ASTRA 19.2E 11817-V-27500, the card can > > > > work very well (no lock issues) for hours. > > > > > > > > On some other transponders, like ASTRA 19.2E 11567-V-22000, the card > > > > nearly never manage to get the lock: it's looking like the signal > > > > isn't good enough. > > > > > > Afaics the problem is caused by the tuning loop > > > for (tm = -6; tm < 7;) > > > in stv0288_set_frontend(). > > > > > > I doubt that this code works reliably. > > > Apparently it never obtains a lock within the given delay (30us). > It's actually quite slow caused by any delay in the I2C bus. I doubt > given the age many controllers run at the 400kHz spec, if barely 100kHz. > > > > > > > Could you please try the attached patch? > > > It disables the loop and tries to tune to the center frequency. > > > > > > > Ok, I've tested this patch with ASTRA 19.2 #24 transponder that wasn't > > always working: it seems to work. > > I think it would be great to test it for few days more to be sure. > > Unfortunately, this patch does not work well at all. > > All that is happening is that the carrier offset is getting forced to 0, > after it has been updated by the lock control register losing a 'good' > lock. > > The value is typically around ~f800+. > > Perhaps the loop should be knocked down slightly to -9. The loop was > probably intended for 22000 symbol rate. The following patch provides wider carrier search. As with existing code search starts at MSB aligned. The boundary is widened to start at -9. In order to save time, if no carrier is detected at the start it advances to the next alignment until carrier is found. The stv0288 will detect a DVB-S2 carrier on all steps , a time out of 11 steps is introduced to drop out of the loop. In stv0288_set_symbol carrier and timing loops are restored to default values (inittab) before setting the symbol rate on each tune. A slight drift was noticed with full scan in the higher IF frequencies of each band. Signed-off-by: Malcolm Priestley <tvboxspy@xxxxxxxxx> --- drivers/media/dvb/frontends/stv0288.c | 29 +++++++++++++++++++++-------- 1 files changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/media/dvb/frontends/stv0288.c b/drivers/media/dvb/frontends/stv0288.c index 8e0cfad..0aa3962 100644 --- a/drivers/media/dvb/frontends/stv0288.c +++ b/drivers/media/dvb/frontends/stv0288.c @@ -127,6 +127,11 @@ static int stv0288_set_symbolrate(struct dvb_frontend *fe, u32 srate) if ((srate < 1000000) || (srate > 45000000)) return -EINVAL; + stv0288_writeregI(state, 0x22, 0); + stv0288_writeregI(state, 0x23, 0); + stv0288_writeregI(state, 0x2b, 0xff); + stv0288_writeregI(state, 0x2c, 0xf7); + temp = (unsigned int)srate / 1000; temp = temp * 32768; @@ -461,6 +466,7 @@ static int stv0288_set_frontend(struct dvb_frontend *fe, char tm; unsigned char tda[3]; + u8 reg, time_out = 0; dprintk("%s : FE_SET_FRONTEND\n", __func__); @@ -488,22 +494,29 @@ static int stv0288_set_frontend(struct dvb_frontend *fe, /* Carrier lock control register */ stv0288_writeregI(state, 0x15, 0xc5); - tda[0] = 0x2b; /* CFRM */ tda[2] = 0x0; /* CFRL */ - for (tm = -6; tm < 7;) { + for (tm = -9; tm < 7;) { /* Viterbi status */ - if (stv0288_readreg(state, 0x24) & 0x8) - break; - - tda[2] += 40; - if (tda[2] < 40) + reg = stv0288_readreg(state, 0x24); + if (reg & 0x8) + break; + if (reg & 0x80) { + time_out++; + if (time_out > 10) + break; + tda[2] += 40; + if (tda[2] < 40) + tm++; + } else { tm++; + tda[2] = 0; + time_out = 0; + } tda[1] = (unsigned char)tm; stv0288_writeregI(state, 0x2b, tda[1]); stv0288_writeregI(state, 0x2c, tda[2]); udelay(30); } - state->tuner_frequency = c->frequency; state->fec_inner = FEC_AUTO; state->symbol_rate = c->symbol_rate; -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
