diff options
Diffstat (limited to 'drivers/tty/n_gsm.c')
| -rw-r--r-- | drivers/tty/n_gsm.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index c43b683b6eb8..90dff8233efd 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -875,7 +875,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, /* dlci->skb is locked by tx_lock */ if (dlci->skb == NULL) { - dlci->skb = skb_dequeue(&dlci->skb_list); + dlci->skb = skb_dequeue_tail(&dlci->skb_list); if (dlci->skb == NULL) return 0; first = 1; @@ -899,8 +899,11 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, /* FIXME: need a timer or something to kick this so it can't get stuck with no work outstanding and no buffer free */ - if (msg == NULL) + if (msg == NULL) { + skb_queue_tail(&dlci->skb_list, dlci->skb); + dlci->skb = NULL; return -ENOMEM; + } dp = msg->data; if (dlci->adaption == 4) { /* Interruptible framed (Packetised Data) */ @@ -971,16 +974,19 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm) static void gsm_dlci_data_kick(struct gsm_dlci *dlci) { unsigned long flags; + int sweep; spin_lock_irqsave(&dlci->gsm->tx_lock, flags); /* If we have nothing running then we need to fire up */ + sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO); if (dlci->gsm->tx_bytes == 0) { if (dlci->net) gsm_dlci_data_output_framed(dlci->gsm, dlci); else gsm_dlci_data_output(dlci->gsm, dlci); - } else if (dlci->gsm->tx_bytes < TX_THRESH_LO) - gsm_dlci_data_sweep(dlci->gsm); + } + if (sweep) + gsm_dlci_data_sweep(dlci->gsm); spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags); } @@ -1190,6 +1196,8 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, u8 *data, int clen) { u8 buf[1]; + unsigned long flags; + switch (command) { case CMD_CLD: { struct gsm_dlci *dlci = gsm->dlci[0]; @@ -1215,7 +1223,9 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, gsm->constipated = 0; gsm_control_reply(gsm, CMD_FCOFF, NULL, 0); /* Kick the link in case it is idling */ + spin_lock_irqsave(&gsm->tx_lock, flags); gsm_data_kick(gsm); + spin_unlock_irqrestore(&gsm->tx_lock, flags); break; case CMD_MSC: /* Out of band modem line change indicator for a DLCI */ @@ -2377,12 +2387,12 @@ static void gsmld_write_wakeup(struct tty_struct *tty) /* Queue poll */ clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); + spin_lock_irqsave(&gsm->tx_lock, flags); gsm_data_kick(gsm); if (gsm->tx_bytes < TX_THRESH_LO) { - spin_lock_irqsave(&gsm->tx_lock, flags); gsm_dlci_data_sweep(gsm); - spin_unlock_irqrestore(&gsm->tx_lock, flags); } + spin_unlock_irqrestore(&gsm->tx_lock, flags); } /** @@ -2889,6 +2899,10 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp) gsm = gsm_mux[mux]; if (gsm->dead) return -EL2HLT; + /* If DLCI 0 is not yet fully open return an error. This is ok from a locking + perspective as we don't have to worry about this if DLCI0 is lost */ + if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) + return -EL2NSYNC; dlci = gsm->dlci[line]; if (dlci == NULL) dlci = gsm_dlci_alloc(gsm, line); |