.PHONY: __clean
__clean:
-include $(if $(wildcard $(obj)/Kbuild), $(obj)/Kbuild, $(obj)/Makefile)
+# The filename Kbuild has precedence over Makefile
+include $(if $(wildcard $(srctree)/$(src)/Kbuild), \
+ $(srctree)/$(src)/Kbuild, $(srctree)/$(src)/Makefile)
# Figure out what we need to build from the various variables
# ==========================================================================