1 files changed, 21 insertions, 16 deletions

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 51dafc06f541..5fea02cfb0cc 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -50,6 +50,7 @@
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/gsmmux.h>
+#include "tty.h"
 
 static int debug;
 module_param(debug, int, 0600);
@@ -266,7 +267,7 @@ struct gsm_mux {
 
 #define MAX_MUX		4			/* 256 minors */
 static struct gsm_mux *gsm_mux[MAX_MUX];	/* GSM muxes */
-static spinlock_t gsm_mux_lock;
+static DEFINE_SPINLOCK(gsm_mux_lock);
 
 static struct tty_driver *gsm_tty_driver;
 
@@ -2384,8 +2385,18 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
 		/* Don't register device 0 - this is the control channel and not
 		   a usable tty interface */
 		base = mux_num_to_base(gsm); /* Base for this MUX */
-		for (i = 1; i < NUM_DLCI; i++)
-			tty_register_device(gsm_tty_driver, base + i, NULL);
+		for (i = 1; i < NUM_DLCI; i++) {
+			struct device *dev;
+
+			dev = tty_register_device(gsm_tty_driver,
+							base + i, NULL);
+			if (IS_ERR(dev)) {
+				for (i--; i >= 1; i--)
+					tty_unregister_device(gsm_tty_driver,
+								base + i);
+				return PTR_ERR(dev);
+			}
+		}
 	}
 	return ret;
 }
@@ -2416,27 +2427,24 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 			      char *fp, int count)
 {
 	struct gsm_mux *gsm = tty->disc_data;
-	const unsigned char *dp;
-	char *f;
-	int i;
 	char flags = TTY_NORMAL;
 
 	if (debug & 4)
 		print_hex_dump_bytes("gsmld_receive: ", DUMP_PREFIX_OFFSET,
 				     cp, count);
 
-	for (i = count, dp = cp, f = fp; i; i--, dp++) {
-		if (f)
-			flags = *f++;
+	for (; count; count--, cp++) {
+		if (fp)
+			flags = *fp++;
 		switch (flags) {
 		case TTY_NORMAL:
-			gsm->receive(gsm, *dp);
+			gsm->receive(gsm, *cp);
 			break;
 		case TTY_OVERRUN:
 		case TTY_BREAK:
 		case TTY_PARITY:
 		case TTY_FRAME:
-			gsm_error(gsm, *dp, flags);
+			gsm_error(gsm, *cp, flags);
 			break;
 		default:
 			WARN_ONCE(1, "%s: unknown flag %d\n",
@@ -2849,7 +2857,6 @@ static int gsm_create_network(struct gsm_dlci *dlci, struct gsm_netconfig *nc)
 /* Line discipline for real tty */
 static struct tty_ldisc_ops tty_ldisc_packet = {
 	.owner		 = THIS_MODULE,
-	.magic           = TTY_LDISC_MAGIC,
 	.name            = "n_gsm",
 	.open            = gsmld_open,
 	.close           = gsmld_close,
@@ -3052,7 +3059,7 @@ static int gsmtty_write_room(struct tty_struct *tty)
 {
 	struct gsm_dlci *dlci = tty->driver_data;
 	if (dlci->state == DLCI_CLOSED)
-		return -EINVAL;
+		return 0;
 	return TX_SIZE - kfifo_len(&dlci->fifo);
 }
 
@@ -3060,7 +3067,7 @@ static int gsmtty_chars_in_buffer(struct tty_struct *tty)
 {
 	struct gsm_dlci *dlci = tty->driver_data;
 	if (dlci->state == DLCI_CLOSED)
-		return -EINVAL;
+		return 0;
 	return kfifo_len(&dlci->fifo);
 }
 
@@ -3261,8 +3268,6 @@ static int __init gsm_init(void)
 	gsm_tty_driver->init_termios.c_lflag &= ~ECHO;
 	tty_set_operations(gsm_tty_driver, &gsmtty_ops);
 
-	spin_lock_init(&gsm_mux_lock);
-
 	if (tty_register_driver(gsm_tty_driver)) {
 		put_tty_driver(gsm_tty_driver);
 		tty_unregister_ldisc(N_GSM0710);