[linux-dvb] KNC DVB-C/CI + Nagravision CAM: discontinuity error flood

Zoilo Gomez zoilo at xs4all.nl
Thu Dec 7 15:05:34 CET 2006

I have a really weird problem with KNC DVB-C/CI + Nagravision CAM, with 
latest hg version, as well as with all other older versions that I have 

Using czap, I can lock properly to all frequencies. On about 2/3 of all 
cable frequencies, I can also watch the channels; however, on about 1/3 
of all cable frequencies, I get an enormous amount of 'Discontinuity 

Over the last days, I have verified that these continuity errors really 
do exist (printks in driver source demux), and that the missing packets 
are really not being delivered by the CAM-module: about 25% of the 
pcakets seem to be missing, and the continuity counter has many gaps, 
sometimes even 2 or more consecutive packets are missing. As soon as I 
unplug the CAM-module, the problem is fixed; if I plug it back in then 
the problem is back.

In other towns (with same provider) the problems exist as well, but on 
different frequencies ....  In fact, I discovered it because one 
frequency that had been working fine for 2 months, suddenly came with 
this problem, causing an enormous log file full of discontinuity errors, 
filling up my /var partition within 12 hours => disk full (!). 
Apparently the TS-multiplexer at the provider plays some role in this as 

Of course, I cannot watch the channels in these streams when they have 
discontinuity errors; on Windows however I can always watch these 
channels seamlessly (quite embarrassing)! Also using a Twinhan Cab/CI 
2031 these same channels are being decoded properly! Here there seems to 
be no discontinuity error problem.

So I guess that the problem seems to be somehow related to the way the 
CAM-module is being initialized or so .... anybody any ideas?


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