DVB tuning with or without Hardware PID filter

bernd_b · 2017-03-07 20:46:53

My question to the kernel experts:
With DVB-reception, there is a procedure called Hardware-PID-Filtering. I understood this means that the DVB-Card filters out all streams which are on the same transponder but not meant to be shown/ recorded.

Is there a switch to turn this on/off with arch?

Background to my question:

I have reception problems with my
Technisat SkyStar S2
DVB-Card:

[dmesg | grep flex
[    8.933808] b2c2-flexcop: B2C2 FlexcopII/II(b)/III digital TV receiver chip loaded successfully
[    9.035092] flexcop-pci: will use the HW PID filter.
[    9.035100] flexcop-pci: card revision 2
[    9.048657] b2c2-flexcop: MAC address = 00:08:c9:e0:bc:d1
[    9.710606] b2c2-flexcop: ISL6421 successfully attached.
[    9.710613] b2c2-flexcop: found 'Conexant CX24120/CX24118' .
[    9.710621] b2c2_flexcop_pci 0000:03:06.0: DVB: registering adapter 0 frontend 0 (Conexant CX24120/CX24118)...
[    9.711729] b2c2-flexcop: initialization of 'Sky2PC/SkyStar S2 DVB-S/S2 rev 3.3' at the 'PCI' bus controlled by a 'FlexCopIIb' complete

Tuning to the Britisch Station ITV HD on Astra 28.2, the picture shows only garbage (using the software vdr).

I tested the same card on the same PC with the same SAT-wire on Windows(XP) and it turns out that I can tune to this station without problems. Using the windows-Software DVBViewer, I can turn on and off Hardware PID Filtering. With Hardware-PID-Filtering turned off, the reception is very(!) likely to the one I experience on my arch-box using vdr meaning no visible problems with Astra 19.2-stations, reception of, eg. BBC ONE HD on Astra 28.2, but failing to tune to ITV HD.
The idea I got in the discussion in the vdr-forum (German Language) is, that the transponder used by ITV-HD has to much bandwith for the PCI-Slot, so filtering done in the software is not possible.

seth · 2017-03-08 07:51:29

run modinfo b2c2-flexcop-pci and read https://wiki.archlinux.org/index.php/Ke … probe.d.2F

bernd_b · 2017-03-09 20:27:21

Thank you very much - some things are just to easy to find by oneself ....

Actually I could turn the corresponding parameter

  enable_pid_filtering= "1"

on and off but in opposite to the use in windows it has no effect.
I come to the guess that this is a bug in the kernel driver with this specific card, meaning Hardware PID filtering is not working. But I am no experts here ...

seth · 2017-03-09 20:46:27

You can check whether the parameter applied by

systool -vm b2c2-flexcop-pci

Unfortunately, I've no expertise in the particular module or even feature either :-(

Arch Linux

#1 2017-03-07 20:46:53

DVB tuning with or without Hardware PID filter

#2 2017-03-08 07:51:29

Re: DVB tuning with or without Hardware PID filter

#3 2017-03-09 20:27:21

Re: DVB tuning with or without Hardware PID filter

#4 2017-03-09 20:46:27

Re: DVB tuning with or without Hardware PID filter

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