When some other headers are included in some makefile it must be 
relative to the current object file processed. When giving the full 
path the make process will search in the kernel tree for the headers.

--- a/drivers/net/wireless/rtl818x/rtl8180/Makefile
+++ b/drivers/net/wireless/rtl818x/rtl8180/Makefile
@@ -2,4 +2,4 @@ rtl8180-objs		:= dev.o rtl8225.o sa2400.
 
 obj-$(CONFIG_RTL8180)	+= rtl8180.o
 
-ccflags-y += -Idrivers/net/wireless/rtl818x
+ccflags-y += -I$(obj)/..
--- a/drivers/net/wireless/rtl818x/rtl8187/Makefile
+++ b/drivers/net/wireless/rtl818x/rtl8187/Makefile
@@ -2,4 +2,4 @@ rtl8187-objs		:= dev.o rtl8225.o leds.o
 
 obj-$(CONFIG_RTL8187)	+= rtl8187.o
 
-ccflags-y += -Idrivers/net/wireless/rtl818x
+ccflags-y += -I$(obj)/..
--- a/drivers/net/wireless/brcm80211/brcmfmac/Makefile
+++ b/drivers/net/wireless/brcm80211/brcmfmac/Makefile
@@ -16,8 +16,8 @@
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 ccflags-y += \
-	-Idrivers/net/wireless/brcm80211/brcmfmac	\
-	-Idrivers/net/wireless/brcm80211/include
+	-I$(obj)		\
+	-I$(obj)/../include
 
 DHDOFILES = \
 	wl_cfg80211.o \
--- a/drivers/net/wireless/brcm80211/brcmsmac/Makefile
+++ b/drivers/net/wireless/brcm80211/brcmsmac/Makefile
@@ -17,9 +17,9 @@
 
 ccflags-y := \
 	-D__CHECK_ENDIAN__ \
-	-Idrivers/net/wireless/brcm80211/brcmsmac \
-	-Idrivers/net/wireless/brcm80211/brcmsmac/phy \
-	-Idrivers/net/wireless/brcm80211/include
+	-I$(obj)				\
+	-I$(obj)/phy				\
+	-I$(obj)/../include
 
 BRCMSMAC_OFILES := \
 	mac80211_if.o \
--- a/drivers/net/wireless/brcm80211/brcmutil/Makefile
+++ b/drivers/net/wireless/brcm80211/brcmutil/Makefile
@@ -16,8 +16,8 @@
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 ccflags-y :=				\
-	-Idrivers/net/wireless/brcm80211/brcmutil \
-	-Idrivers/net/wireless/brcm80211/include
+	-I$(obj)			\
+	-I$(obj)/../include
 
 BRCMUTIL_OFILES := \
 	utils.o
--- a/net/wireless/Makefile
+++ b/net/wireless/Makefile
@@ -18,6 +18,6 @@ cfg80211-$(CONFIG_CFG80211_INTERNAL_REGD
 ccflags-y += -D__CHECK_ENDIAN__
 
 $(obj)/regdb.c: $(src)/db.txt $(src)/genregdb.awk
-	@$(AWK) -f $(srctree)/$(src)/genregdb.awk < $< > $@
+	@$(AWK) -f $(src)/genregdb.awk < $< > $@
 
 clean-files := regdb.c