diff options
Diffstat (limited to 'drivers/tty/n_gsm.c')
| -rw-r--r-- | drivers/tty/n_gsm.c | 61 |
1 files changed, 39 insertions, 22 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 0b1808e3a912..fa92f727fdf8 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -439,7 +439,7 @@ static u8 gsm_encode_modem(const struct gsm_dlci *dlci) modembits |= MDM_RTR; if (dlci->modem_tx & TIOCM_RI) modembits |= MDM_IC; - if (dlci->modem_tx & TIOCM_CD) + if (dlci->modem_tx & TIOCM_CD || dlci->gsm->initiator) modembits |= MDM_DV; return modembits; } @@ -448,7 +448,7 @@ static u8 gsm_encode_modem(const struct gsm_dlci *dlci) * gsm_print_packet - display a frame for debug * @hdr: header to print before decode * @addr: address EA from the frame - * @cr: C/R bit from the frame + * @cr: C/R bit seen as initiator * @control: control including PF bit * @data: following data bytes * @dlen: length of data @@ -548,7 +548,7 @@ static int gsm_stuff_frame(const u8 *input, u8 *output, int len) * gsm_send - send a control frame * @gsm: our GSM mux * @addr: address for control frame - * @cr: command/response bit + * @cr: command/response bit seen as initiator * @control: control byte including PF bit * * Format up and transmit a control frame. These do not go via the @@ -563,11 +563,15 @@ static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) int len; u8 cbuf[10]; u8 ibuf[3]; + int ocr; + + /* toggle C/R coding if not initiator */ + ocr = cr ^ (gsm->initiator ? 0 : 1); switch (gsm->encoding) { case 0: cbuf[0] = GSM0_SOF; - cbuf[1] = (addr << 2) | (cr << 1) | EA; + cbuf[1] = (addr << 2) | (ocr << 1) | EA; cbuf[2] = control; cbuf[3] = EA; /* Length of data = 0 */ cbuf[4] = 0xFF - gsm_fcs_add_block(INIT_FCS, cbuf + 1, 3); @@ -577,7 +581,7 @@ static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) case 1: case 2: /* Control frame + packing (but not frame stuffing) in mode 1 */ - ibuf[0] = (addr << 2) | (cr << 1) | EA; + ibuf[0] = (addr << 2) | (ocr << 1) | EA; ibuf[1] = control; ibuf[2] = 0xFF - gsm_fcs_add_block(INIT_FCS, ibuf, 2); /* Stuffing may double the size worst case */ @@ -611,7 +615,7 @@ static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) static inline void gsm_response(struct gsm_mux *gsm, int addr, int control) { - gsm_send(gsm, addr, 1, control); + gsm_send(gsm, addr, 0, control); } /** @@ -1017,25 +1021,25 @@ static void gsm_control_reply(struct gsm_mux *gsm, int cmd, const u8 *data, * @tty: virtual tty bound to the DLCI * @dlci: DLCI to affect * @modem: modem bits (full EA) - * @clen: command length + * @slen: number of signal octets * * Used when a modem control message or line state inline in adaption * layer 2 is processed. Sort out the local modem state and throttles */ static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, - u32 modem, int clen) + u32 modem, int slen) { 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 - either be 2 or 3 respectively. This is specified in section - 5.4.6.3.7 of the 27.010 mux spec. */ + /* The modem status command can either contain one octet (V.24 signals) + * or two octets (V.24 signals + break signals). This is specified in + * section 5.4.6.3.7 of the 07.10 mux spec. + */ - if (clen == 2) + if (slen == 1) modem = modem & 0x7f; else { brk = modem & 0x7f; @@ -1092,6 +1096,7 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) unsigned int brk = 0; struct gsm_dlci *dlci; int len = clen; + int slen; const u8 *dp = data; struct tty_struct *tty; @@ -1111,6 +1116,7 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) return; dlci = gsm->dlci[addr]; + slen = len; while (gsm_read_ea(&modem, *dp++) == 0) { len--; if (len == 0) @@ -1127,7 +1133,7 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) modem |= (brk & 0x7f); } tty = tty_port_tty_get(&dlci->port); - gsm_process_modem(tty, dlci, modem, clen); + gsm_process_modem(tty, dlci, modem, slen); if (tty) { tty_wakeup(tty); tty_kref_put(tty); @@ -1451,6 +1457,9 @@ static void gsm_dlci_close(struct gsm_dlci *dlci) if (dlci->addr != 0) { tty_port_tty_hangup(&dlci->port, false); kfifo_reset(&dlci->fifo); + /* Ensure that gsmtty_open() can return. */ + tty_port_set_initialized(&dlci->port, 0); + wake_up_interruptible(&dlci->port.open_wait); } else dlci->gsm->dead = true; /* Unregister gsmtty driver,report gsmtty dev remove uevent for user */ @@ -1514,7 +1523,7 @@ static void gsm_dlci_t1(struct timer_list *t) dlci->mode = DLCI_MODE_ADM; gsm_dlci_open(dlci); } else { - gsm_dlci_close(dlci); + gsm_dlci_begin_close(dlci); /* prevent half open link */ } break; @@ -1593,6 +1602,7 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) struct tty_struct *tty; unsigned int modem = 0; int len = clen; + int slen = 0; if (debug & 16) pr_debug("%d bytes for tty\n", len); @@ -1605,12 +1615,14 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) case 2: /* Asynchronous serial with line state in each frame */ while (gsm_read_ea(&modem, *data++) == 0) { len--; + slen++; if (len == 0) return; } + slen++; tty = tty_port_tty_get(port); if (tty) { - gsm_process_modem(tty, dlci, modem, clen); + gsm_process_modem(tty, dlci, modem, slen); tty_kref_put(tty); } fallthrough; @@ -1748,7 +1760,12 @@ static void gsm_dlci_release(struct gsm_dlci *dlci) gsm_destroy_network(dlci); mutex_unlock(&dlci->mutex); - tty_hangup(tty); + /* We cannot use tty_hangup() because in tty_kref_put() the tty + * driver assumes that the hangup queue is free and reuses it to + * queue release_one_tty() -> NULL pointer panic in + * process_one_work(). + */ + tty_vhangup(tty); tty_port_tty_set(&dlci->port, NULL); tty_kref_put(tty); @@ -1800,10 +1817,10 @@ static void gsm_queue(struct gsm_mux *gsm) goto invalid; cr = gsm->address & 1; /* C/R bit */ + cr ^= gsm->initiator ? 0 : 1; /* Flip so 1 always means command */ gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len); - cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */ dlci = gsm->dlci[address]; switch (gsm->control) { @@ -3234,9 +3251,9 @@ static void gsmtty_throttle(struct tty_struct *tty) if (dlci->state == DLCI_CLOSED) return; if (C_CRTSCTS(tty)) - dlci->modem_tx &= ~TIOCM_DTR; + dlci->modem_tx &= ~TIOCM_RTS; dlci->throttled = true; - /* Send an MSC with DTR cleared */ + /* Send an MSC with RTS cleared */ gsmtty_modem_update(dlci, 0); } @@ -3246,9 +3263,9 @@ static void gsmtty_unthrottle(struct tty_struct *tty) if (dlci->state == DLCI_CLOSED) return; if (C_CRTSCTS(tty)) - dlci->modem_tx |= TIOCM_DTR; + dlci->modem_tx |= TIOCM_RTS; dlci->throttled = false; - /* Send an MSC with DTR set */ + /* Send an MSC with RTS set */ gsmtty_modem_update(dlci, 0); } |