diff options
Diffstat (limited to 'drivers/tty/n_gsm.c')
| -rw-r--r-- | drivers/tty/n_gsm.c | 40 |
1 files changed, 36 insertions, 4 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 2ec337612a79..c41dfe40fd23 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -137,6 +137,9 @@ struct gsm_dlci { struct mutex mutex; /* Link layer */ + int mode; +#define DLCI_MODE_ABM 0 /* Normal Asynchronous Balanced Mode */ +#define DLCI_MODE_ADM 1 /* Asynchronous Disconnected Mode */ spinlock_t lock; /* Protects the internal state */ struct timer_list t1; /* Retransmit timer for SABM and UA */ int retries; @@ -1380,7 +1383,13 @@ retry: ctrl->data = data; ctrl->len = clen; gsm->pending_cmd = ctrl; - gsm->cretries = gsm->n2; + + /* If DLCI0 is in ADM mode skip retries, it won't respond */ + if (gsm->dlci[0]->mode == DLCI_MODE_ADM) + gsm->cretries = 1; + else + gsm->cretries = gsm->n2; + mod_timer(&gsm->t2_timer, jiffies + gsm->t2 * HZ / 100); gsm_control_transmit(gsm, ctrl); spin_unlock_irqrestore(&gsm->control_lock, flags); @@ -1467,6 +1476,10 @@ static void gsm_dlci_open(struct gsm_dlci *dlci) * in which case an opening port goes back to closed and a closing port * is simply put into closed state (any further frames from the other * end will get a DM response) + * + * Some control dlci can stay in ADM mode with other dlci working just + * fine. In that case we can just keep the control dlci open after the + * DLCI_OPENING retries time out. */ static void gsm_dlci_t1(unsigned long data) @@ -1480,8 +1493,16 @@ static void gsm_dlci_t1(unsigned long data) if (dlci->retries) { gsm_command(dlci->gsm, dlci->addr, SABM|PF); mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100); - } else + } else if (!dlci->addr && gsm->control == (DM | PF)) { + if (debug & 8) + pr_info("DLCI %d opening in ADM mode.\n", + dlci->addr); + dlci->mode = DLCI_MODE_ADM; + gsm_dlci_open(dlci); + } else { gsm_dlci_close(dlci); + } + break; case DLCI_CLOSING: dlci->retries--; @@ -1499,8 +1520,8 @@ static void gsm_dlci_t1(unsigned long data) * @dlci: DLCI to open * * Commence opening a DLCI from the Linux side. We issue SABM messages - * to the modem which should then reply with a UA, at which point we - * will move into open state. Opening is done asynchronously with retry + * to the modem which should then reply with a UA or ADM, at which point + * we will move into open state. Opening is done asynchronously with retry * running off timers and the responses. */ @@ -2871,11 +2892,22 @@ static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk) static int gsm_carrier_raised(struct tty_port *port) { struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port); + struct gsm_mux *gsm = dlci->gsm; + /* Not yet open so no carrier info */ if (dlci->state != DLCI_OPEN) return 0; if (debug & 2) return 1; + + /* + * Basic mode with control channel in ADM mode may not respond + * to CMD_MSC at all and modem_rx is empty. + */ + if (gsm->encoding == 0 && gsm->dlci[0]->mode == DLCI_MODE_ADM && + !dlci->modem_rx) + return 1; + return dlci->modem_rx & TIOCM_CD; } |