diff -d -urpN busybox.1/util-linux/mdev.c busybox.2/util-linux/mdev.c
--- busybox.1/util-linux/mdev.c	2008-05-31 20:24:36.000000000 +0200
+++ busybox.2/util-linux/mdev.c	2008-06-04 10:32:43.000000000 +0200
@@ -14,10 +14,12 @@
 
 struct globals {
 	int root_major, root_minor;
+	const char *seqfile;
 };
 #define G (*(struct globals*)&bb_common_bufsiz1)
 #define root_major (G.root_major)
 #define root_minor (G.root_minor)
+#define seqfile    (G.seqfile   )
 
 #define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */
 
@@ -386,10 +388,10 @@ static void load_firmware(const char *co
 }
 
 int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int mdev_main(int argc, char **argv)
+int mdev_main(int argc ATTRIBUTE_UNUSED, char **argv)
 {
-	char *action;
-	char *env_path;
+	int opt;
+	int timeout = 1000;
 	RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
 
 #ifdef YOU_WANT_TO_DEBUG_HOTPLUG_EVENTS
@@ -401,9 +403,15 @@ int mdev_main(int argc, char **argv)
 	xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDERR_FILENO);
 #endif
 
+/* TODO: force validity of fds 0,1,2 as in init? */
+
 	xchdir("/dev");
 
-	if (argc == 2 && !strcmp(argv[1], "-s")) {
+	opt_complementary = "t+"; /* -t MSEC */
+	opt = getopt32(argv, "sf:t:", &seqfile, &timeout);
+	/* NB: path in -f FNAME is relative to /dev: /dev/FNAME */
+
+	if (opt & 1) {
 		/* Scan:
 		 * mdev -s
 		 */
@@ -422,8 +430,13 @@ int mdev_main(int argc, char **argv)
 			fileAction, dirAction, temp, 0);
 
 	} else {
+		char *seq = seq; /* for compiler */
+		char *action;
+		char *env_path;
+		char seqbuf[sizeof(int)*3 + 2];
+
 		/* Hotplug:
-		 * env ACTION=... DEVPATH=... mdev
+		 * env ACTION=... DEVPATH=... [SEQNUM=...] mdev
 		 * ACTION can be "add" or "remove"
 		 * DEVPATH is like "/block/sda" or "/class/input/mice"
 		 */
@@ -432,6 +445,22 @@ int mdev_main(int argc, char **argv)
 		if (!action || !env_path)
 			bb_show_usage();
 
+		if (seqfile) {
+			seq = getenv("SEQNUM");
+			if (seq) {
+				timeout >>= 5; /* unsigned /= 32 */
+				do {
+					int len = open_read_close(seqfile, seqbuf, sizeof(seqbuf-1));
+					if (len < 0)
+						break;
+					seqbuf[len] = '\0';
+					if (strcmp(seq, seqbuf) == 0)
+						break;
+					usleep(32*1000);
+				} while (--timeout >= 0);
+			}
+		}
+
 		snprintf(temp, PATH_MAX, "/sys%s", env_path);
 		if (!strcmp(action, "remove"))
 			make_device(temp, 1);
@@ -444,6 +473,10 @@ int mdev_main(int argc, char **argv)
 					load_firmware(fw, temp);
 			}
 		}
+
+		if (seqfile && seq) {
+			xopen_xwrite_close(seqfile, utoa(xatou(seq) + 1));
+		}
 	}
 
 	if (ENABLE_FEATURE_CLEAN_UP)