Messages in this thread | | | Subject | Re: linux-next: Tree for Oct 8 (media/usb/gspca) | From | Paul Bolle <> | Date | Thu, 09 Oct 2014 13:26:10 +0200 |
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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@tiscali.nl> 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
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