From a7f924190924783d3e291624c4f0c3f51481ae2c Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Fri, 23 Mar 2018 22:04:34 +0900
Subject: [PATCH] kbuild: add %.dtb.S and %.dtb to 'targets' automatically

Another common pattern that consists of chained commands is to compile
a DTB as binary data into the kernel image or a module.  It is used in
several places in the source tree.  Support it in the core Makefile.

$(call if_changed,dt_S_dtb) is more suitable than $(call cmd,dt_S_dtb)
in case cmd_dt_S_dtb is changed in the future.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
---
 drivers/of/unittest-data/Makefile | 2 --
 scripts/Makefile.build            | 4 +++-
 scripts/Makefile.lib              | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
index 8fd0ea4b92b08..87a65ca385835 100644
--- a/drivers/of/unittest-data/Makefile
+++ b/drivers/of/unittest-data/Makefile
@@ -21,8 +21,6 @@ obj-$(CONFIG_OF_OVERLAY) += overlay.dtb.o \
 			    overlay_bad_symbol.dtb.o \
 			    overlay_base.dtb.o
 
-targets += $(foreach suffix, dtb dtb.S, $(patsubst %.dtb.o,%.$(suffix),$(obj-y)))
-
 # enable creation of __symbols__ node
 DTC_FLAGS_overlay += -@
 DTC_FLAGS_overlay_bad_phandle += -@
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 36f7990c57012..15b3bbb3248b1 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -544,9 +544,11 @@ targets := $(filter-out $(PHONY), $(targets))
 intermediate_targets = $(foreach sfx, $(2), \
 				$(patsubst %$(strip $(1)),%$(sfx), \
 					$(filter %$(strip $(1)), $(targets))))
+# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
 # %.lex.o <- %.lex.c <- %.l
 # %.tab.o <- %.tab.[ch] <- %.y
-targets += $(call intermediate_targets, .lex.o, .lex.c) \
+targets += $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
+	   $(call intermediate_targets, .lex.o, .lex.c) \
 	   $(call intermediate_targets, .tab.o, .tab.c .tab.h)
 
 # Descending
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index b1d938fab73bc..7f5bca0c3b7ba 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -279,8 +279,8 @@ cmd_dt_S_dtb=						\
 	echo '.balign STRUCT_ALIGNMENT'; 		\
 ) > $@
 
-$(obj)/%.dtb.S: $(obj)/%.dtb
-	$(call cmd,dt_S_dtb)
+$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
+	$(call if_changed,dt_S_dtb)
 
 quiet_cmd_dtc = DTC     $@
 cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
-- 
GitLab