[PATCH] link failur in Linux 2.4.9-ac16 around apm.o and sysrq.o

[junio@siamese.dhis.twinsun.com]

2.4.9-ac16 fails to link with CONFIG_APM=y and
CONFIG_MAGIC_SYSRQ=n.  This is because apm.c unconditionally
makes calls to functions (__sysrq_lock_table and friends)
defined in sysrq.c.

I can think of a couple of different approaches to work this
around, but is there an established proper way to resolve this
kind of dependency in the kernel code?

I've attached a fix based on (3) below at the end of this message.

 (1) In include/linux/sysrq.h, define stubs for
     __sysrq_lock_table that does not do anything when
     CONFIG_MAGIC_SYSRQ is not set;

 (2) Change ''make config'' procedure so that CONFIG_MAGIC_SYSRQ
     is always set if CONFIG_APM is defined;

 (3) Change drivers/char/Makefile to make sysrq.o to be linked
     in if CONFIG_APM is defined (even if CONFIG_MAGIC_SYSRQ is).

--- 2.4.9-ac16.sffix/drivers/char/Makefile	Thu Sep 27 12:46:56 2001
+++ 2.4.9-ac16.sffix/drivers/char/Makefile	Thu Sep 27 22:08:19 2001
@@ -143,6 +143,7 @@
 endif
 
 obj-$(CONFIG_MAGIC_SYSRQ) += sysrq.o
+obj-$(CONFIG_APM) += sysrq.o
 obj-$(CONFIG_ATARI_DSP56K) += dsp56k.o
 obj-$(CONFIG_ROCKETPORT) += rocket.o
 obj-$(CONFIG_MOXA_SMARTIO) += mxser.o