On Thu, 2014-10-09 at 07:30 -0300, Mauro Carvalho Chehab wrote:
> Em Thu, 09 Oct 2014 08:45:28 +0200
> Paul Bolle <pebolle@xxxxxxxxxx> escreveu:
> > The above discussion meanders a bit, and I just stumbled onto it, but
> > would
> > #if IS_BUILTIN(CONFIG_INPUT) || (IS_MODULE(CONFIG_INPUT) && defined(MODULE))
> >
> > cover your requirements when using macros?
>
> No. What we need to do, for all gspca sub-drivers that have optional
> support for buttons is to only enable the buttons support if:
>
> CONFIG_INPUT=y
> or
> CONFIG_INPUT=m and CONFIG_USB_GSPCA_submodule=m
>
> If we use a reverse logic, we need to disable the code if:
> # CONFIG_INPUT is not set
> or
> CONFIG_INPUT=m and CONFIG_USB_GSPCA_submodule=y
>
> The rationale for disabling the code on the last expression is that a
> builtin code cannot call a function inside a module.
>
> Also, as the submodule is already being compiled, we know that
> CONFIG_USB_GSPCA_submodule is either module or builtin.
>
> So, either one of those expressions should work:
> #if (IS_BUILTIN(CONFIG_INPUT)) || (IS_ENABLED(CONFIG_INPUT) && !IS_BUILTIN(CONFIG_USB_GSPCA_submodule))
> or
> #if (IS_BUILTIN(CONFIG_INPUT)) || (IS_MODULE(CONFIG_INPUT) && IS_MODULE(CONFIG_USB_GSPCA_submodule) && defined(MODULE))
I thought MODULE was only defined for code that will be part of a
module. So "IS_MODULE(CONFIG_USB_GSPCA_submodule)" and "defined(MODULE)"
should be equal when used _inside_ [...]/usb/gspca/that_submodule.c,
shouldn't they? That would make this option basically identical to my
suggestion. Or are you thinking about using these tests outside of these
submodules themselves?
> or
> #if (IS_BUILTIN(CONFIG_INPUT)) || (IS_ENABLED(CONFIG_INPUT) && IS_MODULE(CONFIG_USB_GSPCA_submodule))
I think it's clearer to use
IS_BUILTIN(CONFIG_FOO) || (IS_MODULE(CONFIG_FOO) && [...])
Ditto above. Perhaps just a matter of taste.
(Depending on INPUT is apparently not possible for these submodules. So
obviously any solution needs to check whether input is available, say
like
if (IS_MODULE(CONFIG_INPUT))
if (!is_input_loaded())
goto no_input;
Doesn't it?)
Thanks,
Paul Bolle
--
To unsubscribe from this list: send the line "unsubscribe linux-next" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
