Messages in this thread |  | | Date | Tue, 20 Feb 2007 15:59:43 +0100 | From | Adrian Bunk <> | Subject | Re: Kbuild problem |
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On Tue, Feb 20, 2007 at 02:56:27PM +0100, Tilman Schmidt wrote: > Adrian Bunk schrieb: > > On Sun, Feb 18, 2007 at 12:22:10AM -0500, Kai Germaschewski wrote: > >> On Sat, 17 Feb 2007, Tilman Schmidt wrote: > >> > >> > asyncdata.o is only needed for M105 and M101, not for the base > >> > driver. How do I express in Kbuild that asyncdata.o is to be added > >> > to gigaset-y only if CONFIG_GIGASET_M105 and CONFIG_GIGASET_M101 > >> > are not both 'n'? > >> > >> The way this is typically done is via Kconfig. Add a config option > >> ASYNCDATA (actually something more descriptive/specific would be better), > >> add a "select ASYNCDATA" to the config options for m101 and m105, and then > >> you can use CONFIG_ASYNCDATA to decide whether to add asyncdata.o in the > >> Makefile. > > > > One disadvantage of this approach is that in a kernel with > > CONFIG_GIGASET_BASE=y, you can't later compile and load the usb_gigaset > > or ser_gigaset modules without rebooting since they require a change to > > the kernel image. > > You've got a point there. So linking asyncdata.o into the modules that > need it, as it is currently done, would perhaps be better after all? > The original problem (asyncdata.o linked in twice, causing duplicate > symbol definitions) could be fixed with this (admittedly somewhat > awkward) change to the Makefile (build tested): > > --- linux-2.6.20-mm1-work/drivers/isdn/gigaset/Makefile 2007-02-20 13:39:44.000000000 +0100 > +++ u/drivers/isdn/gigaset/Makefile 2007-02-20 13:38:58.000000000 +0100 > @@ -1,7 +1,10 @@ > gigaset-y := common.o interface.o proc.o ev-layer.o i4l.o > usb_gigaset-y := usb-gigaset.o asyncdata.o > bas_gigaset-y := bas-gigaset.o isocdata.o > -ser_gigaset-y := ser-gigaset.o asyncdata.o > +ser_gigaset-y := ser-gigaset.o > +ifneq ($(CONFIG_GIGASET_M101)$(CONFIG_GIGASET_M105),yy) > +ser_gigaset-y += asyncdata.o > +endif
What happens with CONFIG_GIGASET_M101=y, CONFIG_GIGASET_M105=m ?
> obj-$(CONFIG_GIGASET_M105) += usb_gigaset.o gigaset.o > obj-$(CONFIG_GIGASET_BASE) += bas_gigaset.o gigaset.o > > The alternative would be to always link asyncdata.o into the gigaset > module whether it's needed or not. "size asyncdata.o" says: > text data bss dec hex filename > 4200 0 0 4200 1068 asyncdata.o > which appears tolerable. > > Opinions?
I'm usually someone who likes to avoid including unneeded code in the kernel, but in this case I'd say KISS - and build it always into the gigaset module.
> Tilman Schmidt
cu Adrian
--
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