[linux-dvb] [RFC] Should a DVB frontend report the board name?

Marko Ristola marko.ristola at kolumbus.fi
Sun Feb 11 09:15:03 CET 2007


I just read your thread.
I have a bit different suggestion.
This is a hierarcial naming scheme.
I also suggest Tuner numbering with 1 and 2, instead of 0 and 1.

How to separate different devices?
The device drivers aren't supposed to know anything about other devices.

Udev tries to handle device separation and name aliasing.
Applications and libraries could do that separation also.

How to do "device frontend" - "RF component" separation?

Before I bought a PCI card, I wanted to know
that how many RF components (or tuners) it had.
It was important, because then I know that how many different
channels I can see or record at a same time.

Then I decided to buy a card with one tuner.
Usually the RF input is same for both tuners on a card.
There aren't more than one TV antenna or satellite dish.
A single tuner or multiple tuners are always on one card (PCI/USB).

Thus this is my naming suggestion:

Card 1 (two RF components, hierarcial naming scheme):
"TerraTec/qanu USB2.0 Highspeed DVB-T Receiver / Tuner 1"
"TerraTec/qanu USB2.0 Highspeed DVB-T Receiver / Tuner 2"

Card 2 (single RF component):
"TerraTec/qanu USB2.0 Highspeed DVB-T Receiver"

The hierarcial naming scheme would thus work with single and multiple
frontends. Tuner separation is done only when it is necessary.

The average user doesn't need technical numbering starting from zero.
Unfortunately the separate technical (frontend 0) and
user numbering scheme (Tuner 1 ) would cause confusion with
user support. Those who don't need technical support, are
less confused with "Tuner 1" and "Tuner 2".

The application or udev would be responsible to make names look different
if there are two exactly identical cards.

Marko Ristola

Manu Abraham wrote:
> frontend = demod name (that's what we have currently), Tuner is
> unimportant in this case as it doesn't have much of ops.
> for the average person, frontend = RF module, inclusive of the demod
> the problem comes when you have 2 different frontends on one bridge.
> The user get's even more confused. Tune to board frontend 0 /1 ? which
> is frontend 0 which is frontend 1 ?
> There needs to be clear distinction when multiple devices exists.
> So in your case you are always tuning to your board name, irrespective
> of the number of frontends. IMHO, in the case where you had one
> frontend (with demod as name) is not as  confusing compared to this
> scenario.
> Assuming that a board has multiple demods.
>> But ack, we should be as precise as possible.
>> So the next question is: If we have the entries you propose, how do 
>> these
>> get reported to user space? Currently, the API only reports the frontend
>> type.
> In multiproto, there is DVBFE_GET_INFO, working with that as a base.
> It is extendable to the adapter object.
> Currrently playing around with a bit with some devices on the same in
> that aspect
> manu
> _______________________________________________
> linux-dvb mailing list
> linux-dvb at linuxtv.org
> http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb

More information about the linux-dvb mailing list