Re: [RESEND] Re: DViCO FusionHDTV DVB-T Dual Digital 4 (rev 1) tuning regression

[Mauro Carvalho Chehab <mchehab@redhat.com>]

Robert Lowery wrote:
> Mauro's new code does the 500000 offset unconditionally for DTV7 by
> setting offset = 2250000, not just when the ZARLINK456 or DIBCOM52 tables
> were explicitly selected.  This change is what appears to cause issues for
> me.

I've reviewed all information and troubles we have with xc3028 tuning,
including the reports related to newer firmwares for XC3028L. I think
that the right fix is the one provided on this patch.

Could you all please verify if this patch fixes the issues, without causing
any regression?

Cheers,
Mauro.

---

V4L/DVB: tuner-xc2028: fix tuning logic

There's one reported regression in Australia (DTV7) and some
reported troubles with newer firmwares. Rework the logic to improve
tuner on those cases.

Thanks-to: Robert Lowery <rglowery@exemail.com.au>
Thanks-to: Stefan Ringel <stefan.ringel@arcor.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
---
 drivers/media/common/tuners/tuner-xc2028.c |   51 ++++++++++++++++++++--------
 1 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/drivers/media/common/tuners/tuner-xc2028.c b/drivers/media/common/tuners/tuner-xc2028.c
index ed50168..eb782a0 100644
--- a/drivers/media/common/tuners/tuner-xc2028.c
+++ b/drivers/media/common/tuners/tuner-xc2028.c
@@ -932,30 +932,49 @@ static int generic_set_freq(struct dvb_frontend *fe, u32 freq /* in HZ */,
 	 * that xc2028 will be in a safe state.
 	 * Maybe this might also be needed for DTV.
 	 */
-	if (new_mode == T_ANALOG_TV)
+	if (new_mode == T_ANALOG_TV) {
 		rc = send_seq(priv, {0x00, 0x00});
 
-	/*
-	 * Digital modes require an offset to adjust to the
-	 * proper frequency.
-	 * Analog modes require offset = 0
-	 */
-	if (new_mode == T_DIGITAL_TV) {
-		/* Sets the offset according with firmware */
+		/* Analog modes require offset = 0 */
+	} else {
+		/*
+		 * Digital modes require an offset to adjust to the
+		 * proper frequency. The offset depends on what
+		 * firmware version is used.
+		 */
+
+		/*
+		 * Adjust to the center frequency. This is calculated by the
+		 * formula: offset = 1.25MHz - BW/2
+		 * For DTV 7/8, the firmware uses BW = 8000, so it needs a
+		 * further adjustment to get the frequency center on VHF
+		 */
 		if (priv->cur_fw.type & DTV6)
 			offset = 1750000;
 		else if (priv->cur_fw.type & DTV7)
 			offset = 2250000;
 		else	/* DTV8 or DTV78 */
 			offset = 2750000;
+		if ((priv->cur_fw.type & DTV78) && freq < 470000000)
+			offset -= 500000;
 
 		/*
-		 * We must adjust the offset by 500kHz  when
-		 * tuning a 7MHz VHF channel with DTV78 firmware
-		 * (used in Australia, Italy and Germany)
+		 * xc3028 additional "magic"
+		 * Depending on the firmware version, it needs some adjustments
+		 * to properly centralize the frequency. This seems to be
+		 * needed to compensate the SCODE table adjustments made by
+		 * newer firmwares
 		 */
-		if ((priv->cur_fw.type & DTV78) && freq < 470000000)
-			offset -= 500000;
+
+		if (priv->firm_version >= 0x0302) {
+			if (priv->cur_fw.type & DTV7)
+				offset -= 300000;
+			else if (type != ATSC) /* DVB @6MHz, DTV 8 and DTV 7/8 */
+				offset += 200000;
+		} else {
+			if (priv->cur_fw.type & DTV7)
+				offset -= 500000;
+		}
 	}
 
 	div = (freq - offset + DIV / 2) / DIV;
@@ -1114,7 +1133,11 @@ static int xc2028_set_params(struct dvb_frontend *fe,
 
 	/* All S-code tables need a 200kHz shift */
 	if (priv->ctrl.demod) {
-		demod = priv->ctrl.demod + 200;
+		/*
+		 * Newer firmwares require a 200 kHz offset only for ATSC
+		 */
+		if (type == ATSC || priv->firm_version < 0x0302)
+			demod = priv->ctrl.demod + 200;
 		/*
 		 * The DTV7 S-code table needs a 700 kHz shift.
 		 * Thanks to Terry Wu <terrywu2009@gmail.com> for reporting this
-- 
1.6.6.1