1 files changed, 26 insertions, 1 deletions

diff --git a/sys/modules/twe/Makefile b/sys/modules/twe/Makefile
index f12f4e952711..2d0639bcd4e8 100644
--- a/sys/modules/twe/Makefile
+++ b/sys/modules/twe/Makefile
@@ -1,7 +1,32 @@
 # $FreeBSD$
 
+#
+# The 3ware controller offers a choice of options related to handling of
+# mirror consistency in shutdown situations.
+#
+# If TWE_SHUTDOWN_NOTIFICATION is defined, the driver will inform the 
+# controller on clean shutdown.  On reboot after an unclean shutdown, the 
+# controller will perform a complete mirror rebuild.  This is the most
+# "safe" configuration, but it imposes a severe performance penalty in the
+# event of an unexpected reboot.
+#
+# In the alternate configuration, the controller assumes that all writes to
+# a mirror complete successfully.  In the case of an unclean shutdown,
+# mirror corruption may occur if the controller is reset or power is lost
+# during a disk write.  This configuration is more suitable if the system
+# has reliable power, but may be unstable for other reasons.
+#
+CFLAGS+=-DTWE_SHUTDOWN_NOTIFICATION
+
+#
+# The module can be built to override a compiled-in driver
+#
+#CFLAGS+=-DTWE_OVERRIDE
+
 .PATH:	${.CURDIR}/../../dev/twe
 KMOD=	twe
-SRCS=	bus_if.h device_if.h pci_if.h twe.c twe_disk.c
+SRCS=	bus_if.h device_if.h pci_if.h twe.c twe_freebsd.c
+
+#CFLAGS+=-DTWE_DEBUG=0
 
 .include <bsd.kmod.mk>