[linux-dvb] Re: tzap not locking on

[Johannes Stezenbach <js@convergence.de>]

Martin Kenny wrote:
> 
> I think you might be helped by a patch I submitted a while back (but I 
> think got lost in the noise) for 
> linux/drivers/media/dvb/frontends/sp887x.c. It's probably out of sync 
> with CVS (and maybe kernel 2.6.7) right now, but it should be pretty 
> easy to apply by hand.
> 
> See 
> http://www.linuxtv.org/mailinglists/linux-dvb/2004/06-2004/msg00055.html 
> for details.

--- sp887x.c.old        2004-06-01 22:50:06.000000000 +0930
+++ sp887x.c    2004-06-02 18:03:51.154418192 +0930
@@ -636,9 +636,9 @@
       case FE_GET_TUNE_SETTINGS:
       {
               struct dvb_frontend_tune_settings* fesettings = (struct dvb_frontend_tune_settings*) arg;
-               fesettings->min_delay_ms = 50;
-               fesettings->step_size = 0;
-               fesettings->max_drift = 0;
+               fesettings->min_delay_ms = 350;
+               fesettings->step_size = 166666*2;
+               fesettings->max_drift = (166666*2)+1;
               return 0;
       }


Hm, step_size and max_drift > 0 means that the frontend core will
do zig-zag scanning, which I thought was not very useful for DVB-T.
Also 350ms delay seems a bit long.

Anyway, if someone else can confirm that this improves tuning, I
would just commit it.


Johannes