kbuild: do not require sub-make for separate output tree builds
As explained in commit 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some
included Makefiles"), I want to stop using --include-dir some day.
I already fixed up the top Makefile, but some arch Makefiles (mips, um,
x86) still include check-in Makefiles without $(srctree)/.
Fix them up so 'need-sub-make := 1' can go away for this case.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
diff --git a/Makefile b/Makefile
index eae1314..185ce47 100644
--- a/Makefile
+++ b/Makefile
@@ -191,10 +191,9 @@
ifneq ($(abs_srctree),$(abs_objtree))
# Look for make include files relative to root of kernel src
#
-# This does not become effective immediately because MAKEFLAGS is re-parsed
-# once after the Makefile is read. We need to invoke sub-make.
+# --included-dir is added for backward compatibility, but you should not rely on
+# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
MAKEFLAGS += --include-dir=$(abs_srctree)
-need-sub-make := 1
endif
ifneq ($(filter 3.%,$(MAKE_VERSION)),)