*/
struct gsm_msg {
- struct gsm_msg *next;
+ struct list_head list;
u8 addr; /* DLCI address + flags */
u8 ctrl; /* Control byte + flags */
unsigned int len; /* Length of data block (can be zero) */
unsigned int tx_bytes; /* TX data outstanding */
#define TX_THRESH_HI 8192
#define TX_THRESH_LO 2048
- struct gsm_msg *tx_head; /* Pending data packets */
- struct gsm_msg *tx_tail;
+ struct list_head tx_list; /* Pending data packets */
/* Control messages */
struct timer_list t2_timer; /* Retransmit timer for commands */
m->len = len;
m->addr = addr;
m->ctrl = ctrl;
- m->next = NULL;
+ INIT_LIST_HEAD(&m->list);
return m;
}
*
* The tty device has called us to indicate that room has appeared in
* the transmit queue. Ram more data into the pipe if we have any
+ * If we have been flow-stopped by a CMD_FCOFF, then we can only
+ * send messages on DLCI0 until CMD_FCON
*
* FIXME: lock against link layer control transmissions
*/
static void gsm_data_kick(struct gsm_mux *gsm)
{
- struct gsm_msg *msg = gsm->tx_head;
+ struct gsm_msg *msg, *nmsg;
int len;
int skip_sof = 0;
- /* FIXME: We need to apply this solely to data messages */
- if (gsm->constipated)
- return;
-
- while (gsm->tx_head != NULL) {
- msg = gsm->tx_head;
+ list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) {
+ if (gsm->constipated && msg->addr)
+ continue;
if (gsm->encoding != 0) {
gsm->txframe[0] = GSM1_SOF;
len = gsm_stuff_frame(msg->data,
len - skip_sof) < 0)
break;
/* FIXME: Can eliminate one SOF in many more cases */
- gsm->tx_head = msg->next;
- if (gsm->tx_head == NULL)
- gsm->tx_tail = NULL;
gsm->tx_bytes -= msg->len;
- kfree(msg);
/* For a burst of frames skip the extra SOF within the
burst */
skip_sof = 1;
+
+ list_del(&msg->list);
+ kfree(msg);
}
}
msg->data = dp;
/* Add to the actual output queue */
- if (gsm->tx_tail)
- gsm->tx_tail->next = msg;
- else
- gsm->tx_head = msg;
- gsm->tx_tail = msg;
+ list_add_tail(&msg->list, &gsm->tx_list);
gsm->tx_bytes += msg->len;
gsm_data_kick(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;
if (len > gsm->mtu) {
if (dlci->adaption == 3) {
/* Over long frame, bin it */
- kfree_skb(dlci->skb);
+ dev_kfree_skb_any(dlci->skb);
dlci->skb = NULL;
return 0;
}
/* 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) */
skb_pull(dlci->skb, len);
__gsm_data_queue(dlci, msg);
if (last) {
- kfree_skb(dlci->skb);
+ dev_kfree_skb_any(dlci->skb);
dlci->skb = NULL;
}
return size;
static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
{
unsigned long flags;
+ int sweep;
+
+ if (dlci->constipated)
+ return;
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);
}
{
int mlines = 0;
u8 brk = 0;
+ int fc;
/* The modem status command can either contain one octet (v.24 signals)
or two octets (v.24 signals + break signals). The length field will
else {
brk = modem & 0x7f;
modem = (modem >> 7) & 0x7f;
- };
+ }
/* Flow control/ready to communicate */
- if (modem & MDM_FC) {
+ fc = (modem & MDM_FC) || !(modem & MDM_RTR);
+ if (fc && !dlci->constipated) {
/* Need to throttle our output on this device */
dlci->constipated = 1;
- }
- if (modem & MDM_RTC) {
- mlines |= TIOCM_DSR | TIOCM_DTR;
+ } else if (!fc && dlci->constipated) {
dlci->constipated = 0;
gsm_dlci_data_kick(dlci);
}
+
/* Map modem bits */
+ if (modem & MDM_RTC)
+ mlines |= TIOCM_DSR | TIOCM_DTR;
if (modem & MDM_RTR)
mlines |= TIOCM_RTS | TIOCM_CTS;
if (modem & MDM_IC)
{
unsigned int addr = 0;
unsigned int modem = 0;
+ unsigned int brk = 0;
struct gsm_dlci *dlci;
int len = clen;
u8 *dp = data;
if (len == 0)
return;
}
+ len--;
+ if (len > 0) {
+ while (gsm_read_ea(&brk, *dp++) == 0) {
+ len--;
+ if (len == 0)
+ return;
+ }
+ modem <<= 7;
+ modem |= (brk & 0x7f);
+ }
tty = tty_port_tty_get(&dlci->port);
gsm_process_modem(tty, dlci, modem, clen);
if (tty) {
u8 *data, int clen)
{
u8 buf[1];
+ unsigned long flags;
+
switch (command) {
case CMD_CLD: {
struct gsm_dlci *dlci = gsm->dlci[0];
gsm_control_reply(gsm, CMD_TEST, data, clen);
break;
case CMD_FCON:
- /* Modem wants us to STFU */
- gsm->constipated = 1;
- gsm_control_reply(gsm, CMD_FCON, NULL, 0);
- break;
- case CMD_FCOFF:
/* Modem can accept data again */
gsm->constipated = 0;
- gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
+ gsm_control_reply(gsm, CMD_FCON, 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_FCOFF:
+ /* Modem wants us to STFU */
+ gsm->constipated = 1;
+ gsm_control_reply(gsm, CMD_FCOFF, NULL, 0);
break;
case CMD_MSC:
/* Out of band modem line change indicator for a DLCI */
dlci->gsm->dlci[dlci->addr] = NULL;
kfifo_free(dlci->fifo);
while ((dlci->skb = skb_dequeue(&dlci->skb_list)))
- kfree_skb(dlci->skb);
+ dev_kfree_skb(dlci->skb);
kfree(dlci);
}
{
int i;
struct gsm_dlci *dlci = gsm->dlci[0];
- struct gsm_msg *txq;
+ struct gsm_msg *txq, *ntxq;
struct gsm_control *gc;
gsm->dead = 1;
if (gsm->dlci[i])
gsm_dlci_release(gsm->dlci[i]);
/* Now wipe the queues */
- for (txq = gsm->tx_head; txq != NULL; txq = gsm->tx_head) {
- gsm->tx_head = txq->next;
+ list_for_each_entry_safe(txq, ntxq, &gsm->tx_list, list)
kfree(txq);
- }
- gsm->tx_tail = NULL;
+ INIT_LIST_HEAD(&gsm->tx_list);
}
EXPORT_SYMBOL_GPL(gsm_cleanup_mux);
}
spin_lock_init(&gsm->lock);
kref_init(&gsm->ref);
+ INIT_LIST_HEAD(&gsm->tx_list);
gsm->t1 = T1;
gsm->t2 = T2;
gsm->error(gsm, *dp, flags);
break;
default:
- WARN_ONCE("%s: unknown flag %d\n",
+ WARN_ONCE(1, "%s: unknown flag %d\n",
tty_name(tty, buf), flags);
break;
}
/* 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);
}
/**
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);