patch from Jaakko Hyvatti http://hyvatti.iki.fi/~jaakko/dvb/dvb6.diff:

- Makes zigzag to not change frequency for DVB-c at all. It only resets
  the parameters over and over again.                                                                         - The IF of 35937500 might be better to be 36000000. This might be what the
  card designer meant. My card shows the AFC fine tuning offset to be closest
  to zero with 35937500 (one step below 36MHz). Some other cards might be
  different. I have not heard of any complaints about my patch not working
  for someone in this respect.
- Has anyone ever tested this auto inversion thing? DVB-c is far too slow to
  tune and lock for this auto inversion code to work. Therefore you need to
  manually set it. Maybe zigzag changes above allow the auto inversion to work.                               - QAM registers have been tweaked to non-specification values. I do not know
  if someone has counterexamples, but this works for a lot of people.

1 files changed, 2 insertions, 1 deletions

diff --git a/linux/drivers/media/dvb/dvb-core/dvb_frontend.c b/linux/drivers/media/dvb/dvb-core/dvb_frontend.c
index 5009fc164..1eff505f2 100644
--- a/linux/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/linux/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -389,6 +389,8 @@ void dvb_frontend_recover (struct dvb_frontend_data *fe)
 		
 		if (fe->info->type == FE_QPSK)
 			stepsize = fe->parameters.u.qpsk.symbol_rate / 16000;
+		else if (fe->info->type == FE_QAM)
+			stepsize = 0;
 		else
 			stepsize = fe->info->frequency_stepsize * 2;
 
@@ -996,4 +998,3 @@ MODULE_PARM(dvb_frontend_debug,"i");
 MODULE_PARM(dvb_shutdown_timeout,"i");
 MODULE_PARM_DESC(dvb_frontend_debug, "enable verbose debug messages");
 MODULE_PARM_DESC(dvb_shutdown_timeout, "wait <shutdown_timeout> seconds after close() before suspending hardware");
-