[linux-dvb] Lock problems about mt2131

Steven Toth stoth at hauppauge.com
Sat Aug 18 14:45:56 CEST 2007

kevin liu wrote:
> No, I read the status register in tuner set parameters function,  
> it seems locked.
> but my demod chip just can not detect any available signals.
> And I read the registers 0x01, 0x02,0x03,0x04, 0x05,0x06,
> Compare these values to these read through windows driver, these 
> values are not correct
> So I suspect the algorithm provided in the mt2131 driver. de
> Can you help me with this problem?
> Besides, I am developing the au8502 driver, once it is completed, I 
> think I will release
> Auvitek demodulator driver to the Linux kernel source.
> Thank you .
>                                                         Kevin.
> On 8/17/07, *Steven Toth* <stoth at hauppauge.com 
> <mailto:stoth at hauppauge.com>> wrote:
>     kevin liu wrote:
>     > Hi Steven
>     >      I used FUSION HDTV5 USB silver tv card to test my
>     environment, it
>     > is OK.
>     >      And I used auvitek au8502 demodulator, with mt2131 as its
>     tuner.
>     >      I set au8502 to 8VSB mode, and I compile my mt2131.ko
>     module from
>     > the lastest v4l-dvb tree,
>     >      But the signal just can not be locked.
>     >
>     >      How could I debug this problem, could you give me some advice?
>     It the tuner locking? If you put debug messages in the get_status or
>     equivalent function so yuo see the tuner register indicating lock?
>     Is the auvitek au8502 demod driver doing to be an opensource driver?
>     - Steve


Please keep the linux-dvb mailing list CC'd at all times on this thread, 
and reply to all comments inline, not at the beginning of the email. Thanks.

Can you publish a preliminary datasheet for the Demod, or a preliminary 
GPL driver for the demod yet? That might help.

What I/F frequency does the demod need? I suspect the 2131 driver is 
fixed to match the demods it's been implemented against, and will 
probably need to have the I/F determined during dvb_attach in the 
mt2131_config structure.

The MT2131 driver's pretty raw and support for new demods will grow over 
time, it can be easily extended to incorporate your demod's needs.

- Steve

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