[PATCH] dvb: frontend: stv0297: QAM128 tuning improvement

while investigating the QAM_128-issue with the stv0297-driver for the
Cablestar (which is not the same as the one in dvb-kernel CVS, yet), I fixed
it, not by increasing the timeout, but by disabling the corner-detection for
QAM_128 and higher.

This patch has been tested on dvb-kernel cvs, and has been reported to work by
multiple users.  Some cards still need timeout increase on top of this patch.
This will be addressed later.

Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/media/dvb/frontends/stv0297.c b/drivers/media/dvb/frontends/stv0297.c
index 928aca052afe..01eb41990e8a 100644
--- a/drivers/media/dvb/frontends/stv0297.c
+++ b/drivers/media/dvb/frontends/stv0297.c
@@ -606,7 +606,13 @@ static int stv0297_set_frontend(struct dvb_frontend *fe, struct dvb_frontend_par
         stv0297_set_inversion(state, inversion);
 
         /* kick off lock */
-        stv0297_writereg_mask(state, 0x88, 0x08, 0x08);
+        /* Disable corner detection for higher QAMs */
+        if (p->u.qam.modulation == QAM_128 ||
+                p->u.qam.modulation == QAM_256)
+                stv0297_writereg_mask(state, 0x88, 0x08, 0x00);
+        else
+                stv0297_writereg_mask(state, 0x88, 0x08, 0x08);
+
         stv0297_writereg_mask(state, 0x5a, 0x20, 0x00);
         stv0297_writereg_mask(state, 0x6a, 0x01, 0x01);
         stv0297_writereg_mask(state, 0x43, 0x40, 0x40);