On Thursday 20 November 2008, Lopez Cruz, Misael wrote:
> > On Thursday 20 November 2008, [EMAIL PROTECTED] wrote:
> > > + tristate "SoC Audio support for Texas Instruments SDP3430"
> > > + depends on SND_OMAP_SOC && MACH_OMAP_3430SDP
> > > + select SND_OMAP_SOC_MCBSP
> > > + select SND_SOC_TWL4030
> >
> > depends also on TWL4030_CORE, yes?
> The machine driver itself doesn't depend on TWL4030_CORE, but
> TWL4030 SoC codec driver does (sound/soc/codecs/Kconfig)
>
> config SND_SOC_TWL4030
> tristate
> depends on TWL4030_CORE
>
> Although that dependency is overridden by _select_ statement.
No it isn't. Reverse dependencies don't work like you might
expect ... even when there's no ambiguity in walking up a
chain of them, *no* additional dependencies are flagged.
So as you've written it, SND_SOC_TWL4030 will be active,
but not TWL4030_CORE on which it depends.
If you fix that in Kconfig, you'd make a lot of folk
fairly happy ... but there'd be fun ambiguities to cope
with. Example:
config X
select D
config D
depends on (A && B) || C
It's not clear whether to enable both A and B; just C;
or all of them...
Probably asking the user to resolve such issues would be
necessary. Coming up with all the solutions would be a bit
more complex than a Prolog interpreter, since Kconfig uses
tristate logic not boolean.
> What should be the best way to handle this dependency? Directly
> in kconfig entry for each TWL4030-related machine driver?
The least error-prone answer involves no "select" statements
at all, ever. That is, least error-prone in terms of the
output of Kconfig being a valid configuration ... in terms
of minimizing user error, I suggest just adding the single
dependency I mentioned.
- Dave
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