[linux-dvb] Pinnacle PCTV (Dazzle) 300i maybe i2c problems with newer code?

Hartmut Hackmann hartmut.hackmann at t-online.de
Wed Dec 21 23:20:51 CET 2005


Hi, Jose

José Luis Bolos wrote:
> 2005/12/20, Hartmut Hackmann <hartmut.hackmann at t-online.de>:
> 
>>Hi,
>>
>>Tim Small wrote:
>>
>>>José Luis Bolos wrote:
>>>
>>>
>>>>I was the one having problems with the 300i, and I manage to get it
>>>>running with 2.6.12.5 and 20050627, but I'm having the same problems
>>>>as you, there's extreme blockyness and artifacts in audio and video. I
>>>>was starting to think than that may be reception problems, but  maybe
>>>>it isn't. The card is running ok in analog mode. I have tried to get
>>>>the card running in windows with pinnacle's software (which is utterly
>>>>cr**, btw) but it refuses to store the detected digital channels.
>>>>
>>>>Are they (the artifacts) a known bug? is there a way to get the card
>>>>running correctly? Any help is appreciated.
>>>>
>>>>
>>>
>>>If I tune the card under 2.6.12/20050627, and then reboot into 2.6.14.1
>>>+ current CVS, the output looks fine, and works for about 10 seconds, so
>>>it looks like the artefacts are fixed in the current CVS code.  It then
>>>stutters, and stops.  I get this sort of thing in the kernel message log
>>>(saa7134  i2c_debug=2):
>>>
>>
>>Hm, there was a bug in the TS DMA code of the SAA7134. I found and fixed it
>>after the driver update in 2.6.13. This can explain the artefacts. The bug
>>was not visible on all PCs.
>>
> 
> 
> I've applied successfully
> v4l_653_ts_dma_buffer_synchronization_was_inverted.patch (which I
> suppose is the patch you was reffering to) to 2.6.12.5+20050627, but I
> don't know if it has been of any help. Right now reception with
> channels < 850Mhz is flawless, but 850 and higher and unviewable. I
> noticed yesterday that the reception of the first channels was better,
> so it may be an example of the 'sometimes it worked' you were refering
> to.
> 
The patch has nothing to do with the input frequency. If its ok for low
frequencies, it just is ok. I don't know the the exact numbers by heart,
but 850MHz is very close to the upper band limit. There actually is
something wrong in the channel decoder drivers: They set a data structure
describing the frequency limit but they can't know this, the information
has to come from the tuner resp. dvb-pll. I saw that the mt352 sets the
upper limit to 862MHz. The application should refuse to tune a higher
frequency. If the frequency is lower in your case, the problem either
lies in the tuner (mt2050) or in your antenna resp. its wiring.

Best regards
  Hartmut



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