Apply by doing:
        cd /usr/src
        patch -p0 < 018_gdt.patch

And then rebuild your kernel.

Index: sys/dev/ic/gdt_common.c
===================================================================
RCS file: /cvs/src/sys/dev/ic/gdt_common.c,v
retrieving revision 1.26
retrieving revision 1.26.2.1
diff -u -p -r1.26 -r1.26.2.1
--- sys/dev/ic/gdt_common.c	28 Jun 2003 23:56:40 -0000	1.26
+++ sys/dev/ic/gdt_common.c	30 Apr 2004 23:30:40 -0000	1.26.2.1
@@ -58,7 +58,7 @@ int gdt_maxcmds = GDT_MAXCMDS;
 #endif
 
 #define GDT_DRIVER_VERSION 1
-#define GDT_DRIVER_SUBVERSION 1
+#define GDT_DRIVER_SUBVERSION 2
 
 int	gdt_async_event(struct gdt_softc *, int);
 void	gdt_chain(struct gdt_softc *);
@@ -176,19 +176,6 @@ gdt_attach(gdt)
 		return (1);
 	}
 
-	if (!gdt_internal_cmd(gdt, GDT_CACHESERVICE, GDT_MOUNT, 0xffff, 1,
-	    0)) {
-		printf("cache service mount error %d\n",
-		    gdt->sc_status);
-		return (1);
-	}
-
-	if (!gdt_internal_cmd(gdt, GDT_CACHESERVICE, GDT_INIT, GDT_LINUX_OS, 0,
-	    0)) {
-		printf("cache service post-mount initialization error %d\n",
-		    gdt->sc_status);
-		return (1);
-	}
 	cdev_cnt = (u_int16_t)gdt->sc_info;
 
 	/* Detect number of busses */