Note that MAJOR_AUTO is now the default if d_maj is not initialized. This

is more robust and prevents the hijacking of /dev/console for the typical
mistake.

Remove unneeded MAJOR_AUTO uses, it is only needed explicitly now if the
driver source has cross-branch compatibility to old releases.

sys/conf/majors

@@ -4,8 +4,9 @@
 # the current allocation of device major numbers.
 #
 # Unless very special circumstants demand otherwise, all device drivers
-# are able to use the "MAJOR_AUTO" facility for auto-allocating major
-# numbers at runtime.
+# are able to use a dynamically allocated major number.  If the d_maj
+# element of the cdevsw is uninitialized (preferred) or initialized to
+# MAJOR_AUTO, this dynamic allocation will happen.
 # 
 # NOTICE: FreeBSD does not use block major numbers anymore, you neither
 # need to assign nor use a block major number for any device driver any

sys/dev/sab/sab.c

@@ -167,7 +167,6 @@ static struct cdevsw sabtty_cdevsw = {
 	.d_ioctl =	sabttyioctl,
 	.d_poll =	ttypoll,
 	.d_name =	"sabtty",
-	.d_maj =	MAJOR_AUTO,
 	.d_flags =	D_TTY,
 	.d_kqfilter =	ttykqfilter,
 };

sys/dev/zs/zs.c

@@ -157,7 +157,6 @@ static struct cdevsw zstty_cdevsw = {
 	.d_ioctl =	zsttyioctl,
 	.d_poll =	ttypoll,
 	.d_name =	"zstty",
-	.d_maj =	MAJOR_AUTO,
 	.d_flags =	D_TTY,
 	.d_kqfilter =	ttykqfilter,
 };

sys/i386/isa/loran.c

@@ -627,7 +627,6 @@ static struct cdevsw loran_cdevsw = {
 	.d_read =	loranread,
 	.d_write =	loranwrite,
 	.d_name =	"loran",
-	.d_maj =	MAJOR_AUTO,
 };
 
 #endif /* _KERNEL */

sys/kern/subr_devstat.c

@@ -345,7 +345,6 @@ static struct cdevsw devstat_cdevsw = {
 	.d_close =	nullclose,
 	.d_mmap =	devstat_mmap,
 	.d_name =	"devstat",
-	.d_maj =	MAJOR_AUTO,
 };
 
 struct statspage {

sys/net/if.c

@@ -135,7 +135,6 @@ static struct cdevsw net_cdevsw = {
 	.d_close =	netclose,
 	.d_ioctl =	netioctl,
 	.d_name =	"net",
-	.d_maj =	MAJOR_AUTO,
 	.d_kqfilter =	netkqfilter,
 };
 

sys/netncp/ncp_mod.c

@@ -68,7 +68,6 @@ static struct cdevsw ncp_cdevsw = {
 	.d_close =	nullclose,
 	.d_ioctl =	ncp_ioctl,
 	.d_name =	"ncp",
-	.d_maj =	MAJOR_AUTO,
 };
 
 static int ncp_conn_frag_rq(struct ncp_conn *, struct thread *,