sound/hda/Makefile - kernel/lockdown - Git at Google

 snd-hda-core-objs := hda_bus_type.o hdac_bus.o hdac_device.o hdac_sysfs.o \
 	hdac_regmap.o array.o

 snd-hda-core-objs += trace.o
 CFLAGS_trace.o := -I$(src)

 obj-$(CONFIG_SND_HDA_CORE) += snd-hda-core.o
	snd-hda-core-objs := hda_bus_type.o hdac_bus.o hdac_device.o hdac_sysfs.o \
	hdac_regmap.o array.o

	snd-hda-core-objs += trace.o
	CFLAGS_trace.o := -I$(src)

	obj-$(CONFIG_SND_HDA_CORE) += snd-hda-core.o