Subject: Re: linux-next: build failure after merge of the final tree (wireless tree related)

From: Michal Marek <[email-masked]>
Date: Fri, 23 Dec 2011 21:50:48 +0100

Dne 22.12.2011 17:57, Michal Marek napsal(a):
> Dne 22.12.2011 06:58, Stephen Rothwell napsal(a):
>> Hi ,
>>
>> After merging the final tree, today's linux-next build (powerpc
>> allyesconfig) failed like this:
>>
>> drivers/net/wireless/ath/ath6kl/cfg80211.c:27:1: error: expected ')' before 'KBUILD_MODNAME'
>> drivers/net/wireless/ath/ath6kl/cfg80211.c:27:1: error: 'KBUILD_MODNAME' undeclared here (not in a function)
> [...]
>>
>> I can't figure out what goes wrong here.  On the compile command line,
>> KBUILD_MODNAME is not defined, but KBUILD_BASE_NAME is.
> 
> scripts/Makefile.lib says
> # Note: It's possible that one object gets potentially linked into more
> #       than one module. In that case KBUILD_MODNAME will be set to foo_bar,
> #       where foo and bar are the name of the modules.
> 
> but reality does not match this comment:
> modname_flags  = $(if $(filter 1,$(words $(modname))),\
>                  -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))")

Thinking about this more, the comment is wrong. The reason is that with
the the modules builtin, KBUILD_MODNAME is needed to generate names of
commandline options to set module parameters: <module name>.<param
name>. And ath6kl_sdio_ath6kl_usb.<param> would first look silly, second
the name would change if we disabled one of the drivers.

> But I wonder why you need to link all the object files twice? Usually,
> drivers have a foo_common.ko and foo_{usb,pci,whatever}.ko that provide
> the pci/usb/whatever driver.

Another option is to build both drivers in a single module. Or, as a
band-aid, make the two drivers module-only, by adding 'depends on m' to
their Kconfig entries.

Michal