[linux-dvb] twinhan 1025 - problems locking onto signal

Manu Abraham abraham.manu at gmail.com
Mon Aug 13 17:18:19 CEST 2007


On 8/13/07, Simon Kenyon <simon at koala.ie> wrote:
> Manu Abraham wrote:
> > On 8/13/07, Simon Kenyon <simon at koala.ie> wrote:
> >
> >> Simon Kenyon wrote:
> >>
> >>> just bought 3 cards for my mythtv master backend. silly me.
> >>>
> >>> anyway, using szap i find that tuning to a particular channel is at best
> >>> a hit and miss affair.
> >>> i have a 4x16 multiswitch which feeds astra28.2E into these three cards
> >>> and 4 satellite receivers.
> >>> they all get decent signal. i previously had a nexus-s and a technotrend
> >>> 1500ci in the box and they had no problems with the signal.
> >>>
> >>> is there anything i can do - other than binning them?
> >>> i'm using the hg tree of v4l-dvb.
> >>> is there an expermental tree out there with some improvements for this card?
> >>>
> >>>
> >> a data point is that it will not lock onto any signals with a vertical
> >> polarization
> >> but will lock on to signals with a horizontal polarization (at the
> >> second attempt - not the first).
> >> the latter sounds like a timing issue.
> >>
> >
> > Some of the 1025 cards have been very nasty. It resembles an older
> > case where one card would not tune to either vertical (or was it
> > Horizontal) completely stuck at one volytage level.
> >
> > To take a bite at it, load the dst module with verbose=5, module
> > parameter. look at the logs, if you have timing errors you will see
> > them in the log.
> >
> >
> >
> >> i have 5 other receivers and 2 dvb-s cards which have no problems with
> >> the signal coming from the multiswitch to which they are all attached.
> >>
> >> any help or even ideas of what to do to diagnose the problem out there?
> >>
> >
> >
> > just post the logs, will take in a look whether anything's possible.
> >
> >
> here is a log from the machine.
> i performed 3 szaps
> the first is to a station which did not lock (V)
> the second two did (H)
>
> i hope this is enough to diagnose the problem.
>

First get the sources from linuxtv.org, follow the build procedures,
install the drivers

after that look here:
 http://linuxtv.org/hg/v4l-dvb/file/278ff24d5531/linux/drivers/media/dvb/bt8xx/dst.c

     1337 	return dst_command(state, paket, 8);
     1338 }

change it to:

err = dst_command(state, paket, 8);
msleep(200);
return err;

Also at the bginning of the function declare err as int.


Also:

move to the same path in your sources: after line #1646
     1645 		}
     1646 		retval = dst_write_tuna(fe);


add a msleep(200);

do a recompile, reload modules and see whether it helps



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