I fixed this build error in commit 1b1e4ee86e00 ("sh: fix build error for empty CONFIG_BUILTIN_DTB_SOURCE"), but it came back again. Since commit 37c8a5fafa3b ("kbuild: consolidate Devicetree dtb build rules"), the combination of CONFIG_OF_EARLY_FLATTREE=y and CONFIG_USE_BUILTIN_DTB=n results in the following build error: make[1]: *** No rule to make target 'arch/sh/boot/dts/.dtb.o', needed by 'arch/sh/boot/dts/built-in.a'. Stop. make: *** [Makefile;1727: arch/sh/boot/dts/] Error 2 Prior to that commit, there was only one path to descend into arch/sh/boot/dts/, and arch/sh/Makefile correctly guards it with CONFIG_USE_BUILTIN_DTB: core-$(CONFIG_USE_BUILTIN_DTB) += arch/sh/boot/dts/ Now, there is another path to descend there from the top Makefile when CONFIG_OF_EARLY_FLATTREE=y. Add obj-$(CONFIG_USE_BUILTIN_DTB) guard in case CONFIG_BUILTIN_DTB_SOURCE is hidden due to the unmet 'depends on'. Fixes: 37c8a5fafa3b ("kbuild: consolidate Devicetree dtb build rules") Reported-by: kbuild test robot <lkp@xxxxxxxxx> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> --- Observant reviewers may point out another problem. There is a race condition when CONFIG_OF_EARLY_FLATTREE=y. Some architectures (sh, xtensa, etc.) embed a DTB in vmlinux, so there are two paths to descend into arch/*/boot/dts/. For parallel build with -j<N> option, two threads may build under arch/*/boot/dts/ simultaneously. Yes, this is a problem, and it is in my TODO list. For some reasons, I will postpone it by the next development cycle. For now, I want to fix this sh build error first because kbuild test robot is still complaining about it. arch/sh/boot/dts/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/sh/boot/dts/Makefile b/arch/sh/boot/dts/Makefile index 01d0f7f..2563d1e 100644 --- a/arch/sh/boot/dts/Makefile +++ b/arch/sh/boot/dts/Makefile @@ -1,3 +1,3 @@ ifneq ($(CONFIG_BUILTIN_DTB_SOURCE),"") -obj-y += $(patsubst "%",%,$(CONFIG_BUILTIN_DTB_SOURCE)).dtb.o +obj-$(CONFIG_USE_BUILTIN_DTB) += $(patsubst "%",%,$(CONFIG_BUILTIN_DTB_SOURCE)).dtb.o endif -- 2.7.4