1 files changed, 12 insertions, 0 deletions
diff --git a/Makefile b/Makefile
index a250938..ad2cd13 100644
--- a/Makefile
+++ b/Makefile
@@ -41,6 +41,16 @@ ifndef KSRC
 endif
 KINCLUDES:=$(KSRC)/include
 
+# We use the kernel's .config file as an indication that the KSRC
+# directory is indeed a valid and configured kernel source (or partial
+# source) directory.
+KCONFIG:=$(KSRC)/.config
+ifneq (,$(wildcard $(KCONFIG)))
+  HAS_KSRC=yes
+else
+  HAS_KSRC=no
+endif
+
 ifeq (2.6,$(shell echo $(KVERS) | cut -d. -f1-2))
   BUILDVER:=linux26
 else
@@ -556,7 +566,9 @@ clean:
 	rm -f patgen pattest patlooptest hdlcstress hdlctest hdlcgen hdlcverify timertest
 	rm -f *.o ztcfg tzdriver sethdlc sethdlc-new
 	rm -f $(TZOBJS) $(LIBTONEZONE_SO) *.lo
+ifeq (yes,$(HAS_KSRC))
 	$(MAKE) -C $(KSRC) SUBDIRS=$(PWD) clean
+endif
 	$(MAKE) -C wct4xxp clean
 	$(MAKE) -C wctc4xxp clean
 	rm -rf .tmp_versions