Messages in this thread | | | Date | Thu, 2 Aug 2007 17:10:27 +0530 (IST) | From | Satyam Sharma <> | Subject | Re: NETPOLL=y , NETDEVICES=n compile error ( Re: 2.6.23-rc1-mm1 ) |
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[ Read through the thread, looked at Kconfig files, did some tests. Adding Kconfig experts to Cc: list. ]
> On Thu, 2 Aug 2007, Sam Ravnborg wrote: > > > > > > > > > ... > > > > endif # NETDEVICES > > > > > > > > config NETPOLL > > > > depends on NETDEVICES > > > > def_bool NETCONSOLE > > > > > > > > config NETPOLL_TRAP > > > > bool "Netpoll traffic trapping" > > > > default n > > > > depends on NETPOLL > > > > > > > > config NET_POLL_CONTROLLER > > > > def_bool NETPOLL > > > > depends on NETPOLL
Gargh, what we're seeing here is a whole bunch of bugs, I think. First I thought this must be one of those randconfig-producing-wrong-configs issues, but surprisingly, running "make oldconfig" on this .config on a fresh 2.6.23-rc1-mm1 tree didn't change anything in the .config.
Kconfig bug #1: ===============
Which means, although:
***** menuconfig BAZ
if BAZ
config BAR
endif *****
is widely believed (by most folks, I've heard this on several threads, and as written in the comment in drivers/net/Kconfig) to be equivalent to:
***** menuconfig BAZ
if BAZ endif
config BAR depends on BAZ *****
this is *not* enforced by "make oldconfig"! And hence, the NETPOLL && !NETDEVICES situation we're seeing here.
[ We could also categorize this as a bug in Kconfig's "if", fwiw. ]
Kconfig bug #2: ===============
config FOO def_bool BAR
is supposed to ensure that FOO == BAR (as Matt mentioned earlier).
However, even this is *not* enforced by "make oldconfig". And hence, the NETPOLL && !NET_POLL_CONTROLLER situation we're seeing here.
In fact, I believe it's possible to even pass a NETCONSOLE but !NETPOLL kind of .config through "make oldconfig" but it still won't catch it, and build breakages *will* occur.
[ We could also categorize this as a bug in Kconfig's "def_bool", fwiw. ]
Possibly, we could also decide to just blame "randconfig" for the whole issue, and forget about these, because I think it's highly unlikely (though not impossible) for people with "real" .configs to hit the problems we saw above.
KGDBOE bug #1: ==============
config KGDBOE in lib/Kconfig.kgdb must also "depend on" NETDEVICES, and select NET_POLL_CONTROLLER also.
KGDBOE bug #2: ==============
config KGDBOE_NOMODULE is a sad, sad option, and must be killed. The "if !KGDBOE_NOMODULE" in KGDBOE must be removed, and it must lose its dependency on "m".
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