[linux-dvb] [PATCH] Some changes to the Kbuild help

Trent Piepho xyzzy at speakeasy.org
Thu Mar 30 01:01:34 CEST 2006


On Wed, 29 Mar 2006, Michael Krufky wrote:
> I don't want us all to have to constantly update Kconfig each time a new
> card is added. Nobody is going to want to do this, and then the job
> falls on Mauro or I to keep it updated. I would simply remove the card
> names.

I suspected someone might say this, and was going to give up searching google
for the standard names of the cards, but figured I'd stick it out and see what
happened.  There is information here, now, that is useful to people.  So why
hide it?  I tried to word the text so it was implied that the lists are not a
definitive reference.  Maybe if it were more explicit?  Couldn't the argument
that documentation could grow out of date be used against providing any
documentation at all?  Not that I want to give developers more reasons to not
write docs....

How about an update to Documentation/dvb/cards.txt, would that be ok?  And
maybe just a pointer to it from the cx88 Kconfig?

> option for advanced frontend support very recently.  If the user wants
> to tweak the kernel to this extent, then the user cn look on the card to
> find out which demod chip is being used his/her self.

Except that the demod chip is inside a metal can that's covered up by a
sticker.  You can't find the demod chip by looking at the card.  If I wanted
to find out, I'd use google, which might turn up this very email message on a
list archive somewhere.

> > 6) cx88 VP-3054 support needs cx88 MT352 support
>
> Please leave this alone.  As it stands right now:

I did this to fix the kernel config menu.  This is what it looks like with the
change, I hope this makes it though email ok:

<M> Conexant 2388x (bt878 successor) support
< >   Conexant 2388x DMA audio support
<M>   DVB/ATSC Support for cx2388x based TV cards
[ ]     Build all supported frontends for cx2388x based TV cards
---       DVB-S (satellite) frontends
[ ]       Conexant CX24123 DVB-S Support
---       DVB-T (terrestrial) frontends
[ ]       Conexant CX22702 DVB-T Support
[*]       Zarlink MT352 DVB-T Support
<M>         VP-3054 Secondary I2C Bus Support
[ ]       Zarlink ZL10353 DVB-T Support
---       ATSC (North American/Korean Terresterial/Cable DTV) frontends
          and so on...

In case that didn't make it, cx88 dvb is a suboption that appears under cx88
support when cx88 is turned on.  "Build all frontends" appears under cx88 dvb.
If build all frontends is turned OFF, then all the frontends appear under it.
VP3054 is an option under mt352 and appears when mt352 is turned on.
Everything looks as it should.

Now this is what you get without the change:

<M> Conexant 2388x (bt878 successor) support
< >   Conexant 2388x DMA audio support
<M>   DVB/ATSC Support for cx2388x based TV cards
[ ]     Build all supported frontends for cx2388x based TV cards
---       DVB-S (satellite) frontends
[ ]       Conexant CX24123 DVB-S Support
---       DVB-T (terrestrial) frontends
[ ]       Conexant CX22702 DVB-T Support
[*]       Zarlink MT352 DVB-T Support
<M> VP-3054 Secondary I2C Bus Support
[ ] Zarlink ZL10353 DVB-T Support
--- ATSC (North American/Korean Terresterial/Cable DTV) frontends

Everything is the same until you get to VP-3054 support.  Rather than
appearing under MT352, it goes back up to the top level as if it is another
video adapter.  Everything after it is messed up as well.  All the remaining
frontends for cx88 appear directly under the top level, instead of under
cx88 -> cx88-dvb -> frontends.

It's somewhat harder to put into an email message, but the option tree from
xconfig is messed up the same way.

Is there another way to fix this?

> > +	  All selected demodulators will be loaded by the cx88-dvb
> > +	  driver, even those which your card does not need.
> > +
> > +	  Demodulators selected here will automatically be enabled
> > +	  under Digital Video Broadcasting Devices -> Customise DVB
> > +	  Frontends.  Demodulators which are not enabled here, but
> > +	  are enabled under "Customise DVB Frontends" will still NOT
> > +	  be supported by cx2388x based cards.
>
> This is just wrong.  If it is chosen in either menu, then it is enabled.

Opps, how about this then:

          All selected demodulators will be loaded by the cx88-dvb
          driver, even those which your card does not need.

          Demodulators selected here will automatically be enabled
          under Digital Video Broadcasting Devices -> Customise DVB
          Frontends.  Demodulators enabled under "Customise DVB Frontends",
	  but not here, will still be supported by cx2388x based cards.

This is correct, right?

Suppose I have a pcHDTV HD-3000, which is cx88 + or51132, and sometimes
connect a uDigiTV DVB-T USB adapter, which uses a mt352.  This means the
cx88-dvb driver will have mt352 support, even if it isn't turned on under cx88
frontend support.  When the cx8-dvb driver is loaded, it will need to load
or51132 and mt352, even though mt352 isn't used.  There is no way to compile a
cx88-dvb which only needs or51132 and still have digitv which needs mt352.

Unless the cx88 Makefile used VIDEO_CX88_DVB_FRONTENDFOO instead of
DVB_FRONTENDFOO, then you could do this.  Not that I'm providing a patch to
change this, I'm just saying it has a use.



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