[linux-dvb] Re: Problems with WinTV NOVA-CI

[Andrew de Quincey <adq_dvb@lidskialf.net>]

> > If it were in an upper layer (i.e. not tied to specific hardware),
> > reloading the drivers would fix the saa7146 based budget cards. It does
> > not. Therefore it is highly unlikely to be a bug in the upper driver
> > layers. I've been through this line of thought several times already :(
>
> Thanks. But:
> I'm afraid I don't get your logic: "If it were in an upper layer..."
> And what if if the upper layer is doing wrong things?

What I mean is - there aren't really many upper (driver) layers involved here: 
basically tuning,  softdemux, and en50221.

Tuning we know always works OK.

People see this problem without en50221, so it can be ignored.

Softdemux works as follows: 
* The demodulator delivers the entire transport stream to the saa7146.
* The saa7146 sends the entire transport stream across the PCI bus.
* The saa7146 driver gets an interrupt when data is ready, pulls the data from 
the card, and sends it into the soft demuxer.
* The soft demuxer extracts the PIDs the user wants and discards the rest.

The only thing that could go wrong is if the soft demux failed to call the 
card specific start_feed()/stop_feed() implementations. These calls setup the 
saa7146 to start sending data across the PCI bus, and stop sending it 
respectively. I've just realised I'd assumed they worked fine as I've never 
seen them fail - totally stupid mistake now I come to think of it.

However, this is a possibility - it would be good if you could check this, as 
well as someone with the VDR/FF+budget problem. Basically set the 
"budget_debug" parameter to 3 on the budget-core module. You should be able 
to check if the calls to budget_start_feed()/budget_stop_feed() are happening 
in dmesg.

Another thing to check would be to add some debugging printks into 
budget-core.c/start_ts_capture() and budget-core.c/stop_ts_capture() to 
ensure it is getting all the way through those functions - also that the 
correct paths are being taken.

Michael, is there any way we can check if the saa7146 is receiving data from 
the demodulator, even though it may not be sending data over the PCI bus for 
some reason?

BTW: sorry if I sound annoyed, I'm just really frustrated with this 
problem! :)