[DVB] TT S-1500b tuning issue

[DVB] TT S-1500b tuning issue

[Sébastien RAILLARD (COEXSI)]

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.
I turned on the debugging of the stb6000 and stv0288 modules, but I can't
see anything wrong.

Also, we have noticed that the lock maybe lost by intermittence on others
transponders where it may work fine for few hours and then stop working for
few hours.

After doing some researches about the ALPS BSBE1-D01A frontend, I've found
it's the one used in the DREAMBOX DVB-S tuner module (that is running
Linux), but I didn't manage to find the source code repository to check
their drivers, maybe someone know where is it?

Best regards,
Sebastien.

[PATCH] STV0288 Fast Channel Acquisition

[Malcolm Priestley]

On Wed, 2011-06-29 at 15:16 +0200, Sébastien RAILLARD (COEXSI) wrote:

> 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.
> I turned on the debugging of the stb6000 and stv0288 modules, but I can't
> see anything wrong.

I have had similar problems with the stv0288 on astra 19.2 and 28.2 with
various frequencies.

I have been using this patch for some time which seems to improve
things.

The STV0288 has a fast channel function which eliminates
the need for software carrier search.

The patch removes the slow carrier search and replaces
it with this faster and more reliable built-in chip function.

If carrier is lost while channel is running, fast channel
attempts to recover it.

The patch also reguires registers 50-57 to be set correctly
with inittab. All current combinations in the kernel media
tree have been checked and tested.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
---
 drivers/media/dvb/frontends/stv0288.c |   75 +++++++++++++++++++++-----------
 1 files changed, 49 insertions(+), 26 deletions(-)

diff --git a/drivers/media/dvb/frontends/stv0288.c b/drivers/media/dvb/frontends/stv0288.c
index 8e0cfad..fa5cba5 100644
--- a/drivers/media/dvb/frontends/stv0288.c
+++ b/drivers/media/dvb/frontends/stv0288.c
@@ -142,6 +142,12 @@ static int stv0288_set_symbolrate(struct dvb_frontend *fe, u32 srate)
 		stv0288_writeregI(state, 0x28, b[0]);
 		stv0288_writeregI(state, 0x29, b[1]);
 		stv0288_writeregI(state, 0x2a, b[2]);
+
+		stv0288_writeregI(state, 0x22, 0x0);
+		stv0288_writeregI(state, 0x23, 0x0);
+		stv0288_writeregI(state, 0x2b, 0x0);
+		stv0288_writeregI(state, 0x2c, 0x0);
+
 		dprintk("stv0288: stv0288_set_symbolrate\n");
 
 	return 0;
@@ -309,12 +315,13 @@ static u8 stv0288_inittab[] = {
 	0xf1, 0x0,
 	0xf2, 0xc0,
 	0x51, 0x36,
-	0x52, 0x09,
-	0x53, 0x94,
-	0x54, 0x62,
-	0x55, 0x29,
-	0x56, 0x64,
-	0x57, 0x2b,
+	0x52, 0x21,
+	/* Fast Channel MIN/MAX Freqency Bounds MSB bit 7 sets stop */
+	0x53, 0x94, /*Min MSB (0-6)*/
+	0x54, 0x62, /*Min LSB*/
+	0x55, 0x29, /*Max MSB (0-6)*/
+	0x56, 0x64, /*Max LSB*/
+	0x57, 0x2b, /* Increment (signed) */
 	0xff, 0xff,
 };
 
@@ -356,6 +363,35 @@ static int stv0288_init(struct dvb_frontend *fe)
 	return 0;
 }
 
+/* STV0288 Fast channel accquisition and blind search */
+static int stv0288_get_fast(struct dvb_frontend *fe)
+{
+	struct stv0288_state *state = fe->demodulator_priv;
+	int timeout = 0;
+
+	/* Coarse Tune */
+	stv0288_writeregI(state, 0x50, 0x35);
+	/* Wait 15ms */
+	msleep(15);
+	/* Fine Tune Control & Center Carrier */
+	stv0288_writeregI(state, 0x50, 0x16);
+	/* Check for Timing lock */
+	while (!(stv0288_readreg(state, 0x1e) & 0x80)) {
+		if (timeout++ > 5)
+			return -EINVAL;
+		msleep(15);
+	}
+
+	/* Center Carrier for further length of time */
+	stv0288_writeregI(state, 0x50, 0x14);
+	udelay(500);
+	/* Fast Search End*/
+	stv0288_writeregI(state, 0x50, 0x10);
+
+	return 0;
+}
+
+
 static int stv0288_read_status(struct dvb_frontend *fe, fe_status_t *status)
 {
 	struct stv0288_state *state = fe->demodulator_priv;
@@ -369,6 +405,9 @@ static int stv0288_read_status(struct dvb_frontend *fe, fe_status_t *status)
 	*status = 0;
 	if (sync & 0x80)
 		*status |= FE_HAS_CARRIER | FE_HAS_SIGNAL;
+		else
+		stv0288_get_fast(fe); /*try to recover*/
+
 	if (sync & 0x10)
 		*status |= FE_HAS_VITERBI;
 	if (sync & 0x08) {
@@ -458,9 +497,7 @@ static int stv0288_set_frontend(struct dvb_frontend *fe,
 {
 	struct stv0288_state *state = fe->demodulator_priv;
 	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-
-	char tm;
-	unsigned char tda[3];
+	int ret = 0;
 
 	dprintk("%s : FE_SET_FRONTEND\n", __func__);
 
@@ -487,28 +524,14 @@ static int stv0288_set_frontend(struct dvb_frontend *fe,
 	stv0288_set_symbolrate(fe, c->symbol_rate);
 	/* Carrier lock control register */
 	stv0288_writeregI(state, 0x15, 0xc5);
-
-	tda[0] = 0x2b; /* CFRM */
-	tda[2] = 0x0; /* CFRL */
-	for (tm = -6; tm < 7;) {
-		/* Viterbi status */
-		if (stv0288_readreg(state, 0x24) & 0x8)
-			break;
-
-		tda[2] += 40;
-		if (tda[2] < 40)
-			tm++;
-		tda[1] = (unsigned char)tm;
-		stv0288_writeregI(state, 0x2b, tda[1]);
-		stv0288_writeregI(state, 0x2c, tda[2]);
-		udelay(30);
-	}
+	/* Search for carrier */
+	ret = stv0288_get_fast(fe);
 
 	state->tuner_frequency = c->frequency;
 	state->fec_inner = FEC_AUTO;
 	state->symbol_rate = c->symbol_rate;
 
-	return 0;
+	return ret;
 }
 
 static int stv0288_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
-- 
1.7.4.1

RE: [PATCH] STV0288 Fast Channel Acquisition

[Sébastien RAILLARD (COEXSI)]

> -----Original Message-----
> From: linux-media-owner@vger.kernel.org [mailto:linux-media-
> owner@vger.kernel.org] On Behalf Of Malcolm Priestley
> Sent: vendredi 1 juillet 2011 00:22
> To: Linux Media Mailing List
> Cc: Sébastien RAILLARD (COEXSI)
> Subject: [PATCH] STV0288 Fast Channel Acquisition
> 
> On Wed, 2011-06-29 at 15:16 +0200, Sébastien RAILLARD (COEXSI) wrote:
> 
> > 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.
> > I turned on the debugging of the stb6000 and stv0288 modules, but I
> > can't see anything wrong.
> 
> I have had similar problems with the stv0288 on astra 19.2 and 28.2 with
> various frequencies.
> 
> I have been using this patch for some time which seems to improve
> things.
> 
> The STV0288 has a fast channel function which eliminates the need for
> software carrier search.
> 
> The patch removes the slow carrier search and replaces it with this
> faster and more reliable built-in chip function.
> 
> If carrier is lost while channel is running, fast channel attempts to
> recover it.
> 
> The patch also reguires registers 50-57 to be set correctly with
> inittab. All current combinations in the kernel media tree have been
> checked and tested.
> 

Thanks Macolm for this patch!

Regarding the TT-S-1500b, it's using a specific inittab, I hope Oliver can have a look and check if this patch is compatible with the ALPS BSBE1 tuner.

Sebastien

> Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
> ---
>  drivers/media/dvb/frontends/stv0288.c |   75 +++++++++++++++++++++-----
> ------
>  1 files changed, 49 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/media/dvb/frontends/stv0288.c
> b/drivers/media/dvb/frontends/stv0288.c
> index 8e0cfad..fa5cba5 100644
> --- a/drivers/media/dvb/frontends/stv0288.c
> +++ b/drivers/media/dvb/frontends/stv0288.c
> @@ -142,6 +142,12 @@ static int stv0288_set_symbolrate(struct
> dvb_frontend *fe, u32 srate)
>  		stv0288_writeregI(state, 0x28, b[0]);
>  		stv0288_writeregI(state, 0x29, b[1]);
>  		stv0288_writeregI(state, 0x2a, b[2]);
> +
> +		stv0288_writeregI(state, 0x22, 0x0);
> +		stv0288_writeregI(state, 0x23, 0x0);
> +		stv0288_writeregI(state, 0x2b, 0x0);
> +		stv0288_writeregI(state, 0x2c, 0x0);
> +
>  		dprintk("stv0288: stv0288_set_symbolrate\n");
> 
>  	return 0;
> @@ -309,12 +315,13 @@ static u8 stv0288_inittab[] = {
>  	0xf1, 0x0,
>  	0xf2, 0xc0,
>  	0x51, 0x36,
> -	0x52, 0x09,
> -	0x53, 0x94,
> -	0x54, 0x62,
> -	0x55, 0x29,
> -	0x56, 0x64,
> -	0x57, 0x2b,
> +	0x52, 0x21,
> +	/* Fast Channel MIN/MAX Freqency Bounds MSB bit 7 sets stop */
> +	0x53, 0x94, /*Min MSB (0-6)*/
> +	0x54, 0x62, /*Min LSB*/
> +	0x55, 0x29, /*Max MSB (0-6)*/
> +	0x56, 0x64, /*Max LSB*/
> +	0x57, 0x2b, /* Increment (signed) */
>  	0xff, 0xff,
>  };
> 
> @@ -356,6 +363,35 @@ static int stv0288_init(struct dvb_frontend *fe)
>  	return 0;
>  }
> 
> +/* STV0288 Fast channel accquisition and blind search */ static int
> +stv0288_get_fast(struct dvb_frontend *fe) {
> +	struct stv0288_state *state = fe->demodulator_priv;
> +	int timeout = 0;
> +
> +	/* Coarse Tune */
> +	stv0288_writeregI(state, 0x50, 0x35);
> +	/* Wait 15ms */
> +	msleep(15);
> +	/* Fine Tune Control & Center Carrier */
> +	stv0288_writeregI(state, 0x50, 0x16);
> +	/* Check for Timing lock */
> +	while (!(stv0288_readreg(state, 0x1e) & 0x80)) {
> +		if (timeout++ > 5)
> +			return -EINVAL;
> +		msleep(15);
> +	}
> +
> +	/* Center Carrier for further length of time */
> +	stv0288_writeregI(state, 0x50, 0x14);
> +	udelay(500);
> +	/* Fast Search End*/
> +	stv0288_writeregI(state, 0x50, 0x10);
> +
> +	return 0;
> +}
> +
> +
>  static int stv0288_read_status(struct dvb_frontend *fe, fe_status_t
> *status)  {
>  	struct stv0288_state *state = fe->demodulator_priv; @@ -369,6
> +405,9 @@ static int stv0288_read_status(struct dvb_frontend *fe,
> fe_status_t *status)
>  	*status = 0;
>  	if (sync & 0x80)
>  		*status |= FE_HAS_CARRIER | FE_HAS_SIGNAL;
> +		else
> +		stv0288_get_fast(fe); /*try to recover*/
> +
>  	if (sync & 0x10)
>  		*status |= FE_HAS_VITERBI;
>  	if (sync & 0x08) {
> @@ -458,9 +497,7 @@ static int stv0288_set_frontend(struct dvb_frontend
> *fe,  {
>  	struct stv0288_state *state = fe->demodulator_priv;
>  	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
> -
> -	char tm;
> -	unsigned char tda[3];
> +	int ret = 0;
> 
>  	dprintk("%s : FE_SET_FRONTEND\n", __func__);
> 
> @@ -487,28 +524,14 @@ static int stv0288_set_frontend(struct
> dvb_frontend *fe,
>  	stv0288_set_symbolrate(fe, c->symbol_rate);
>  	/* Carrier lock control register */
>  	stv0288_writeregI(state, 0x15, 0xc5);
> -
> -	tda[0] = 0x2b; /* CFRM */
> -	tda[2] = 0x0; /* CFRL */
> -	for (tm = -6; tm < 7;) {
> -		/* Viterbi status */
> -		if (stv0288_readreg(state, 0x24) & 0x8)
> -			break;
> -
> -		tda[2] += 40;
> -		if (tda[2] < 40)
> -			tm++;
> -		tda[1] = (unsigned char)tm;
> -		stv0288_writeregI(state, 0x2b, tda[1]);
> -		stv0288_writeregI(state, 0x2c, tda[2]);
> -		udelay(30);
> -	}
> +	/* Search for carrier */
> +	ret = stv0288_get_fast(fe);
> 
>  	state->tuner_frequency = c->frequency;
>  	state->fec_inner = FEC_AUTO;
>  	state->symbol_rate = c->symbol_rate;
> 
> -	return 0;
> +	return ret;
>  }
> 
>  static int stv0288_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
> --
> 1.7.4.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media"
> in the body of a message to majordomo@vger.kernel.org More majordomo
> info at  http://vger.kernel.org/majordomo-info.html

RE: [PATCH] STV0288 Fast Channel Acquisition

[Malcolm Priestley]

On Fri, 2011-07-01 at 10:15 +0200, Sébastien RAILLARD (COEXSI) wrote:
> 
> > -----Original Message-----
> > From: linux-media-owner@vger.kernel.org [mailto:linux-media-
> > owner@vger.kernel.org] On Behalf Of Malcolm Priestley
> > Sent: vendredi 1 juillet 2011 00:22
> > To: Linux Media Mailing List
> > Cc: Sébastien RAILLARD (COEXSI)
> > Subject: [PATCH] STV0288 Fast Channel Acquisition
> > 
> > On Wed, 2011-06-29 at 15:16 +0200, Sébastien RAILLARD (COEXSI) wrote:
> > 
> > > 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.
> > > I turned on the debugging of the stb6000 and stv0288 modules, but I
> > > can't see anything wrong.
> > 
> > I have had similar problems with the stv0288 on astra 19.2 and 28.2 with
> > various frequencies.
> > 
> > I have been using this patch for some time which seems to improve
> > things.
> > 
> > The STV0288 has a fast channel function which eliminates the need for
> > software carrier search.
> > 
> > The patch removes the slow carrier search and replaces it with this
> > faster and more reliable built-in chip function.
> > 
> > If carrier is lost while channel is running, fast channel attempts to
> > recover it.
> > 
> > The patch also reguires registers 50-57 to be set correctly with
> > inittab. All current combinations in the kernel media tree have been
> > checked and tested.
> > 
> 
> Thanks Macolm for this patch!
> 
> Regarding the TT-S-1500b, it's using a specific inittab, I hope Oliver can have a look and check if this patch is compatible with the ALPS BSBE1 tuner.
> 
> Sebastien
> 
For some reason, I have had nothing but trouble today testing this patch
scanning and tuning certain frequencies. Especially 11426V on Astra
28.2.

So this patch is for review only and marked not applicable on Patchwork.

tvboxspy

Re: [DVB] TT S-1500b tuning issue

[Oliver Endriss]

[-- Attachment #1: Type: text/plain, Size: 1168 bytes --]

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).

Could you please try the attached patch?
It disables the loop and tries to tune to the center frequency.

CU
Oliver

-- 
----------------------------------------------------------------
VDR Remote Plugin 0.4.0: http://www.escape-edv.de/endriss/vdr/
4 MByte Mod: http://www.escape-edv.de/endriss/dvb-mem-mod/
Full-TS Mod: http://www.escape-edv.de/endriss/dvb-full-ts-mod/
----------------------------------------------------------------

[-- Attachment #2: stv0288-scan-disable.diff --]
[-- Type: text/x-diff, Size: 769 bytes --]

diff --git a/drivers/media/dvb/frontends/stv0288.c b/drivers/media/dvb/frontends/stv0288.c
index 8e0cfad..4ffe7da 100644
--- a/drivers/media/dvb/frontends/stv0288.c
+++ b/drivers/media/dvb/frontends/stv0288.c
@@ -488,6 +488,10 @@ static int stv0288_set_frontend(struct dvb_frontend *fe,
 	/* Carrier lock control register */
 	stv0288_writeregI(state, 0x15, 0xc5);
 
+#if 1 /* TEST */
+	stv0288_writeregI(state, 0x2b, 0);
+	stv0288_writeregI(state, 0x2c, 0);
+#else
 	tda[0] = 0x2b; /* CFRM */
 	tda[2] = 0x0; /* CFRL */
 	for (tm = -6; tm < 7;) {
@@ -503,6 +507,7 @@ static int stv0288_set_frontend(struct dvb_frontend *fe,
 		stv0288_writeregI(state, 0x2c, tda[2]);
 		udelay(30);
 	}
+#endif
 
 	state->tuner_frequency = c->frequency;
 	state->fec_inner = FEC_AUTO;

RE: [DVB] TT S-1500b tuning issue

[Sébastien RAILLARD (COEXSI)]

> -----Original Message-----
> From: Oliver Endriss [mailto:o.endriss@gmx.de]
> 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).
> 
> 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.

> CU
> Oliver
> 
> --
> ----------------------------------------------------------------
> VDR Remote Plugin 0.4.0: http://www.escape-edv.de/endriss/vdr/
> 4 MByte Mod: http://www.escape-edv.de/endriss/dvb-mem-mod/
> Full-TS Mod: http://www.escape-edv.de/endriss/dvb-full-ts-mod/
> ----------------------------------------------------------------

RE: [DVB] TT S-1500b tuning issue

[Malcolm Priestley]

On Wed, 2011-07-06 at 13:34 +0200, Sébastien RAILLARD (COEXSI) wrote:
> 
> > -----Original Message-----
> > From: Oliver Endriss [mailto:o.endriss@gmx.de]
> > 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.

tvboxspy

[PATCH] STV0288 frontend provide wider carrier search and DVB-S2 drop out.

[Malcolm Priestley]

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@gmx.de]
> > > 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@gmail.com>
---
 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