Re: RFC: kconfig select warnings bogus?

Satyam Sharma
2007-05-19T23:22:14Z

On 5/20/07, Satyam Sharma <satyam.sharma@gmail.com> wrote:
> On 5/20/07, Adrian Bunk <bunk@stusta.de> wrote:
> > On Sat, May 19, 2007 at 11:09:44AM -0700, Andrew Morton wrote:
> > > On Sat, 19 May 2007 17:15:23 +0200 Sam Ravnborg <sam@ravnborg.org> wrote:
> > >
> > > > We see a lot of these lately:
> > > > GEN /home/bor/build/linux-2.6.22/Makefile
> > > > scripts/kconfig/conf -s arch/i386/Kconfig
> > > > drivers/macintosh/Kconfig:116:warning: 'select' used by config symbol 'PMAC_APM_EMU' refers to undefined symbol 'SYS_SUPPORTS_APM_EMULATION'
> > > > drivers/net/Kconfig:2283:warning: 'select' used by config symbol 'UCC_GETH' refers to undefined symbol 'UCC_FAST'
> > > > drivers/input/keyboard/Kconfig:170:warning: 'select' used by config symbol 'KEYBOARD_ATARI' refers to undefined symbol 'ATARI_KBD_CORE'
> > > > drivers/input/mouse/Kconfig:182:warning: 'select' used by config symbol 'MOUSE_ATARI' refers to undefined symbol 'ATARI_KBD_CORE'
> > > >
> > > >
> > > > Do this warning really add any value or should we just ignore them like this?
> > > >
> > >
> > > They always indicate Kconfig bugs, don't they? If so, we should keep the
> > > warning.
> > >...
> >
> > No, they aren't always.
> >
> > Look for example at the last one in drivers/input/mouse/Kconfig:
> >
> > config MOUSE_ATARI
> > tristate "Atari mouse"
> > depends on ATARI
> > select ATARI_KBD_CORE
> >
> > This is perfectly correct (the select'ed symbol is only unavailable when
> > the dependency can't be fulfilled), and all things to "fix" the warning
> > will make it worse.
>
> Not sure what you mean here. The select'ed symbol here is unavailable
> because not all arch's define it. However, the symbol that selects it is
> in drivers/input/... and hence run for all arch's. That's the simple issue
> here that is resolved by this fix.

And by the way, this is precisely the case for _all_ the select issues in this
patch (the four that were raised by Sam) -- i.e. only one arch defining a
config option that is selected by stuff in drivers/... which is common for
all archs, and hence the warnings on other archs.

I don't see any problem at all that is introduced / "made worse" by the
patch, it just rectifies the problem to get rid of the warnings.