diff options
| -rw-r--r-- | drivers/tty/n_gsm.c | 117 |
1 files changed, 79 insertions, 38 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 5a0fd35ce1f9..e8c0ce114c07 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 */ @@ -464,6 +465,68 @@ static void gsm_hex_dump_bytes(const char *fname, const u8 *data, } /** + * 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 * @addr: address EA from the frame @@ -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; } /** |