[linux-dvb] Re: CX88 i2c issue w/ DVB tuners

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

On Friday 10 Sep 2004 11:02, John Dalgliesh wrote:
> On Fri, 10 Sep 2004, Andrew de Quincey wrote:
> > On Thursday 09 Sep 2004 23:41, Gerd Knorr wrote:
> > > > Just hope there isn't a card out there with both DVB AND analogue
> > > > tuners on it....
> > >
> > > class isn't a value but a bitmask, so you can actually say the card
> > > can do both analog and digital tv ...
> >
> > Ah right cool. Eurgh, nasty problem waiting down the line when those
> > cards Holger mentioned appear.
>
> I don't think I understand the condition you are worried about. Do you
> mean that the card has to have two separate (i2c-addressable) tuners, one
> for analogue and one for digital? Or would a card that has one tuner that
> does both like <http://www.dvico.com/products_mul_hd3.html> be a worry?
>
> Just wondering :)

If the card is marked as both analogue and digital, and happens to use one of 
the i2c addresses which several devices use, you could end up with the wrong 
i2c device associated with the wrong device - e.g. the tda9987 (analogue 
tuner) driver was being used incorrectly as the driver for the cx22702 
(digtial demodulator) because they both commonly reside at the same i2c 
address. And theres no way to detect the tda9887 more specifically.

Gah, if only Philips had mandated that all i2c devices must have a unique 32 
bit identifier!