diff -ur alsa-driver-0.9.2.orig/drivers/serialmidi.c alsa-driver-0.9.2/drivers/serialmidi.c
--- alsa-driver-0.9.2.orig/drivers/serialmidi.c	2003-02-22 09:37:11.000000000 +0000
+++ alsa-driver-0.9.2/drivers/serialmidi.c	2003-04-25 00:13:17.000000000 +0100
@@ -33,6 +33,7 @@
 #define SNDRV_GET_ID
 #include <sound/initval.h>
 #include <linux/delay.h>
+#include <asm/atomic.h>
 
 #define SNDRV_SERIAL_MAX_OUTS		16 /* min 16 */
 #define TX_BUF_SIZE			256
@@ -155,7 +156,11 @@
 		retval = -EIO;
 		goto __end;
 	}
-	if (tty->count > 1) {
+	/* tty->count may have changed from int to atomic_t. */
+	/* There is no preprocessor test, so use an ugly cast as a  */
+	/* temporary workaround.  */
+	/* Warning: Assumes int and atomic_t are bit-identical! */
+	if (atomic_read((atomic_t *)&tty->count) > 1) {
 		snd_printk(KERN_ERR "tty %s is already used", serial->sdev);
 		retval = -EBUSY;
 		goto __end;