diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 5a0fd35ce1f9cb50ca8451350fd5cb839beedb10..e8c0ce114c07625f40cb56a035a502ff7f35fb32 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -235,6 +235,7 @@ struct gsm_mux {
struct gsm_dlci *dlci[NUM_DLCI];
int old_c_iflag; /* termios c_iflag value before attach */
bool constipated; /* Asked by remote to shut up */
+ bool has_devices; /* Devices were registered */
spinlock_t tx_lock;
unsigned int tx_bytes; /* TX data outstanding */
@@ -463,6 +464,68 @@ static void gsm_hex_dump_bytes(const char *fname, const u8 *data,
kfree(prefix);
}
+/**
+ * gsm_register_devices - register all tty devices for a given mux index
+ *
+ * @driver: the tty driver that describes the tty devices
+ * @index: the mux number is used to calculate the minor numbers of the
+ * ttys for this mux and may differ from the position in the
+ * mux array.
+ */
+static int gsm_register_devices(struct tty_driver *driver, unsigned int index)
+{
+ struct device *dev;
+ int i;
+ unsigned int base;
+
+ if (!driver || index >= MAX_MUX)
+ return -EINVAL;
+
+ base = index * NUM_DLCI; /* first minor for this index */
+ for (i = 1; i < NUM_DLCI; i++) {
+ /* Don't register device 0 - this is the control channel
+ * and not a usable tty interface
+ */
+ dev = tty_register_device(gsm_tty_driver, base + i, NULL);
+ if (IS_ERR(dev)) {
+ if (debug & 8)
+ pr_info("%s failed to register device minor %u",
+ __func__, base + i);
+ for (i--; i >= 1; i--)
+ tty_unregister_device(gsm_tty_driver, base + i);
+ return PTR_ERR(dev);
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * gsm_unregister_devices - unregister all tty devices for a given mux index
+ *
+ * @driver: the tty driver that describes the tty devices
+ * @index: the mux number is used to calculate the minor numbers of the
+ * ttys for this mux and may differ from the position in the
+ * mux array.
+ */
+static void gsm_unregister_devices(struct tty_driver *driver,
+ unsigned int index)
+{
+ int i;
+ unsigned int base;
+
+ if (!driver || index >= MAX_MUX)
+ return;
+
+ base = index * NUM_DLCI; /* first minor for this index */
+ for (i = 1; i < NUM_DLCI; i++) {
+ /* Don't unregister device 0 - this is the control
+ * channel and not a usable tty interface
+ */
+ tty_unregister_device(gsm_tty_driver, base + i);
+ }
+}
+
/**
* gsm_print_packet - display a frame for debug
* @hdr: header to print before decode
@@ -2204,6 +2267,10 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc)
del_timer_sync(&gsm->t2_timer);
/* Free up any link layer users and finally the control channel */
+ if (gsm->has_devices) {
+ gsm_unregister_devices(gsm_tty_driver, gsm->num);
+ gsm->has_devices = false;
+ }
for (i = NUM_DLCI - 1; i >= 0; i--)
if (gsm->dlci[i])
gsm_dlci_release(gsm->dlci[i]);
@@ -2227,6 +2294,7 @@ static void gsm_cleanup_mux(struct gsm_mux *gsm, bool disc)
static int gsm_activate_mux(struct gsm_mux *gsm)
{
struct gsm_dlci *dlci;
+ int ret;
timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);
init_waitqueue_head(&gsm->event);
@@ -2238,9 +2306,14 @@ static int gsm_activate_mux(struct gsm_mux *gsm)
else
gsm->receive = gsm1_receive;
+ ret = gsm_register_devices(gsm_tty_driver, gsm->num);
+ if (ret)
+ return ret;
+
dlci = gsm_dlci_alloc(gsm, 0);
if (dlci == NULL)
return -ENOMEM;
+ gsm->has_devices = true;
gsm->dead = false; /* Tty opens are now permissible */
return 0;
}
@@ -2500,39 +2573,14 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
* will need moving to an ioctl path.
*/
-static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
+static void gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
{
- unsigned int base;
- int ret, i;
-
gsm->tty = tty_kref_get(tty);
/* Turn off tty XON/XOFF handling to handle it explicitly. */
gsm->old_c_iflag = tty->termios.c_iflag;
tty->termios.c_iflag &= (IXON | IXOFF);
- ret = gsm_activate_mux(gsm);
- if (ret != 0)
- tty_kref_put(gsm->tty);
- else {
- /* 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++) {
- 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;
}
-
/**
* gsmld_detach_gsm - stop doing 0710 mux
* @tty: tty attached to the mux
@@ -2543,12 +2591,7 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm)
{
- unsigned int base = mux_num_to_base(gsm); /* Base for this MUX */
- int i;
-
WARN_ON(tty != gsm->tty);
- for (i = 1; i < NUM_DLCI; i++)
- tty_unregister_device(gsm_tty_driver, base + i);
/* Restore tty XON/XOFF handling. */
gsm->tty->termios.c_iflag = gsm->old_c_iflag;
tty_kref_put(gsm->tty);
@@ -2640,7 +2683,6 @@ static void gsmld_close(struct tty_struct *tty)
static int gsmld_open(struct tty_struct *tty)
{
struct gsm_mux *gsm;
- int ret;
if (tty->ops->write == NULL)
return -EINVAL;
@@ -2656,12 +2698,11 @@ static int gsmld_open(struct tty_struct *tty)
/* Attach the initial passive connection */
gsm->encoding = 1;
- ret = gsmld_attach_gsm(tty, gsm);
- if (ret != 0) {
- gsm_cleanup_mux(gsm, false);
- mux_put(gsm);
- }
- return ret;
+ gsmld_attach_gsm(tty, gsm);
+
+ timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);
+
+ return 0;
}
/**