[linux-dvb] Re: lgdt330x.c 8VSB snr reg not read from chip?

Michael Krufky mkrufky at linuxtv.org
Wed Jun 21 18:45:46 CEST 2006

Harry Coin wrote:
> Wilson & Group:
> Thanks for the attention.  Getting some idea of signal strength at the 
> DVIco Fusion light tuner really matters when trying to debug reception 
> / cabling / amp distribution problems.
> In a related matter, I find that the M$ version of the software 
> running on the same box has no problems finding all the local UHF ATSC 
> stations, but the Linux version doesn't seem to have the tuning right 
> for the ATSC station broadcasting here on UHF channel 49.    I notice 
> some frequency tables end in 0000 and others end a fixed offset up 
> from that.
> Last, as it happens I write device drivers for a living as well.  I'd 
> like to read the datasheets for the chips used in the DVICo Fusion 
> Lite, particularly the tuner related ones.  Can you help with links to 
> those?  I'm thinking of cooking up a little reception diagnostic tool 
> that would have made my struggles easier.  I'm willing to put in the 
> time to understand the chipsets. 

Which kernel version are you running?  There was a typo in the tuner 
frequency range definition, and that might explain your difficulty in 
tuning certain stations.  I believe that the fix was applied late in the 
2.6.16.y series, and it is already in 2.6.17.

You can upgrade your driver to the current version in the v4l-dvb master 
mercurial repository hosted on linuxtv.org, which already contains the 
tuner fix, and the snr reg fix provided earlier in this thread.

http://linuxtv.org/repo  (howto)

Hope this helps,

Michael Krufky

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