Kbuild: Use dtc's -d (dependency) option

This hooks dtc into Kbuild's dependency system.

Thus, for example, "make dtbs" will rebuild tegra-harmony.dtb if only
tegra20.dtsi has changed yet tegra-harmony.dts has not. The previous
lack of this feature recently caused me to have very confusing "git
bisect" results.

For ARM, it's obvious what to add to $(targets). I'm not familiar enough
with other architectures to know what to add there. Powerpc appears to
already add various .dtb files into $(targets), but the other archs may
need something added to $(targets) to work.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
[mmarek: Dropped arch/c6x part to avoid merging commits from the middle
of the merge window]
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 1 insertions, 1 deletions

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 2ce2e2194f26..00c368c6e996 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -264,7 +264,7 @@ $(obj)/%.dtb.S: $(obj)/%.dtb
         $(call cmd,dt_S_dtb)
 
 quiet_cmd_dtc = DTC     $@
-cmd_dtc = $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) $<
+cmd_dtc = $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) -d $(depfile) $<
 
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