Hello together!

I'm the owner of a Terratec Grabster AV400, which is supported by the 
pvrusb2 (currently standalone version only). Video works well, but I 
have a problem with audio, when I use an unmodified v4l-dvb: the audio 
is too slow, as if the bitrate is set to low.

The device contains a cx25837-3 (according to dmesg) and audio routing 
has to be set to CX25840_AUDIO_SERIAL.

The problem now is, that this audio route setting is never applied, 
because there are (at least) two locations in cx25840-core.c where a 
check with is_cx2583x is done.
Locally I've simply disabled that checks (see attached patch) and the 
AV400 works as expected now. Of course this can't be the correct 
solution for the official v4l. Also I have to apply that patch after 
every kernel update (which happens rather often with ArchLinux ^^).

Thus I ask how this situation might be solved so that I can use the 
AV400 without patching around in the source of v4l.

Attached:
* dmesg output with unpatched cx25840 module
* my "quick & dirty" patch for cx25840-core.c

Regards,
Sven