Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751917Ab1CJCj7 (ORCPT ); Wed, 9 Mar 2011 21:39:59 -0500 Received: from mail-wy0-f174.google.com ([74.125.82.174]:41663 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750Ab1CJCj5 (ORCPT ); Wed, 9 Mar 2011 21:39:57 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:content-type:date:message-id:mime-version :x-mailer:content-transfer-encoding; b=etI5+A95qiZ+U/PkbSX5RgT+XkoFhWp7V7RfjUH6oSiGMN4aSbX2anAacyE7xtL1Ic 4rn25bj26QHeQ6J0F+j5LFOIcHZFxxtX3rJrvZoWE7imqW5tGblZyvXFjJUnmckWbJlI /Sm0k3VJ8CUBLZQ8aJ5zqJ2R2EKDyCns3MY2E= Subject: [PATCH n_gsm] GSM Mux in non-transparent mode From: =?ISO-8859-1?Q?M=E1rio?= Isidoro To: gregkh@suse.de Cc: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Date: Thu, 10 Mar 2011 02:39:50 +0000 Message-ID: <1299724790.1800.135.camel@Paio> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9677 Lines: 328 These alterations allow the usage of the non-transparent mode of the gsm mux, it works well enough to establish a ppp session using pppd. The increased buffer size allows the usage of the default MRU and MTU sizes in pppd. Tested with a Telit GE863-Pro^3. This is my first attempt at a patch so I think it is rather crude, suggestions are welcomed :) There is a problem that happens if the process that is holding the attached line discipline tries to detach it before a process using a virtual com manages to close it. Both processes end up dealocked. I think this has to do with the tty lock. I don't have the backtrace with me Signed-off-by: Mário Isidoro diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index aa2e5d3..c244292 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -77,8 +77,8 @@ module_param(debug, int, 0600); * Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte * limits so this is plenty */ -#define MAX_MRU 512 -#define MAX_MTU 512 +#define MAX_MRU 2048 +#define MAX_MTU 2048 /* * Each block of data we have queued to go out is in the form of @@ -417,6 +417,30 @@ static u8 gsm_encode_modem(const struct gsm_dlci *dlci) } /** + * gsm_print_modem - Print modem control lines + * @dlci: DLCI to encode from + * + * Print the status of the modem control lines + */ + +static void gsm_print_modem(int mlines) +{ + pr_debug("Modem lines: %04X\n", mlines); + pr_debug(" RTS:\t%s\n", + ((mlines & TIOCM_RTS) == TIOCM_RTS) ? ("ON") : ("OFF")); + pr_debug(" CTS:\t%s\n", + ((mlines & TIOCM_CTS) == TIOCM_CTS) ? ("ON") : ("OFF")); + pr_debug(" DSR:\t%s\n", + ((mlines & TIOCM_DSR) == TIOCM_DSR) ? ("ON") : ("OFF")); + pr_debug(" DTR:\t%s\n", + ((mlines & TIOCM_DTR) == TIOCM_DTR) ? ("ON") : ("OFF")); + pr_debug(" DCD:\t%s\n", + ((mlines & TIOCM_CD) == TIOCM_CD) ? ("ON") : ("OFF")); + pr_debug(" RI :\t%s\n", + ((mlines & TIOCM_RI) == TIOCM_RI) ? ("ON") : ("OFF")); +} + +/** * gsm_print_packet - display a frame for debug * @hdr: header to print before decode * @addr: address EA from the frame @@ -588,7 +612,7 @@ static void gsm_send(struct gsm_mux *gsm, int addr, int cr, int control) return; } gsm->output(gsm, cbuf, len); - gsm_print_packet("-->", addr, cr, control, NULL, 0); + gsm_print_packet("->-", addr, cr, control, NULL, 0); } /** @@ -999,22 +1023,25 @@ static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data, static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci, u32 modem) { - int mlines = 0; + int mlines = dlci->modem_tx; u8 brk = modem >> 6; + modem = modem >> 1 ; + /* Flow control/ready to communicate */ if (modem & MDM_FC) { + pr_debug("Flux throttled\n"); /* Need to throttle our output on this device */ dlci->constipated = 1; } if (modem & MDM_RTC) { - mlines |= TIOCM_DSR | TIOCM_DTR; + mlines |= TIOCM_DSR ; dlci->constipated = 0; gsm_dlci_data_kick(dlci); } /* Map modem bits */ if (modem & MDM_RTR) - mlines |= TIOCM_RTS | TIOCM_CTS; + mlines |= TIOCM_CTS; if (modem & MDM_IC) mlines |= TIOCM_RI; if (modem & MDM_DV) @@ -1068,18 +1095,25 @@ static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen) return; dlci = gsm->dlci[addr]; - while (gsm_read_ea(&modem, *dp++) == 0) { - len--; - if (len == 0) - return; + + /* Signals frame comes with EA = 0 in GE863-PRO3*/ + if (len == 1) { + modem = *dp ; + } else { + while (gsm_read_ea(&modem, *dp++) == 0) { + len--; + if (len == 0) + return; + } } + tty = tty_port_tty_get(&dlci->port); gsm_process_modem(tty, dlci, modem); if (tty) { tty_wakeup(tty); tty_kref_put(tty); } - gsm_control_reply(gsm, CMD_MSC, data, clen); + /*gsm_control_reply(gsm, CMD_MSC, data, clen);*/ } /** @@ -1234,6 +1268,10 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, /* Rejected by the other end */ if (command == CMD_NSC) ctrl->error = -EOPNOTSUPP; + if (command == CMD_MSC) { + /* Out of band modem line change indicator for a DLCI */ + gsm_control_modem(gsm, data, clen); + } ctrl->done = 1; wake_up(&gsm->event); } @@ -1251,7 +1289,7 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, static void gsm_control_transmit(struct gsm_mux *gsm, struct gsm_control *ctrl) { struct gsm_msg *msg = gsm_data_alloc(gsm, 0, ctrl->len + 1, - gsm->ftype|PF); + gsm->ftype/*|PF*/); if (msg == NULL) return; msg->data[0] = (ctrl->cmd << 1) | 2 | EA; /* command */ @@ -1548,6 +1586,7 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len) { /* See what command is involved */ unsigned int command = 0; + pr_debug("%d bytes of command data\n", len); while (len-- > 0) { if (gsm_read_ea(&command, *data++) == 1) { int clen = *data++; @@ -1555,8 +1594,10 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, u8 *data, int len) /* FIXME: this is properly an EA */ clen >>= 1; /* Malformed command ? */ - if (clen > len) + if (clen > len) { + pr_debug("Malformed Command\n"); return; + } if (command & 1) gsm_control_message(dlci->gsm, command, data, clen); @@ -1673,7 +1714,7 @@ static void gsm_queue(struct gsm_mux *gsm) cr = gsm->address & 1; /* C/R bit */ - gsm_print_packet("<--", address, cr, gsm->control, gsm->buf, gsm->len); + 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]; @@ -1706,7 +1747,7 @@ static void gsm_queue(struct gsm_mux *gsm) break; case UA: case UA|PF: - if (cr == 0 || dlci == NULL) + if (dlci == NULL) break; switch (dlci->state) { case DLCI_CLOSING: @@ -2017,6 +2058,9 @@ int gsm_activate_mux(struct gsm_mux *gsm) dlci = gsm_dlci_alloc(gsm, 0); if (dlci == NULL) return -ENOMEM; + /* At least Siemens/Cinterion and Telit modems require that the control + channel be open within 5 seconds of starting the cmux mode */ + gsm_dlci_begin_open(dlci); gsm->dead = 0; /* Tty opens are now permissible */ return 0; } @@ -2093,7 +2137,7 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) return -ENOSPC; } if (debug & 4) { - pr_debug("-->%d bytes out\n", len); + pr_debug("%d bytes out\n", len); hex_packet(data, len); } gsm->tty->ops->write(gsm->tty, data, len); @@ -2150,7 +2194,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, char flags; if (debug & 4) { - pr_debug("Inbytes %dd\n", count); + pr_debug("%d bytes in\n", count); hex_packet(cp, count); } @@ -2508,10 +2552,10 @@ static int gsmtty_modem_update(struct gsm_dlci *dlci, u8 brk) len++; modembits[0] = len << 1 | EA; /* Data bytes */ - modembits[1] = dlci->addr << 2 | 3; /* DLCI, EA, 1 */ - modembits[2] = gsm_encode_modem(dlci) << 1 | EA; + modembits[1] = (dlci->addr << 2) | 3; /* DLCI, EA, 1 */ + modembits[2] = gsm_encode_modem(dlci) << 1 /*| EA*/; if (brk) - modembits[3] = brk << 4 | 2 | EA; /* Valid, EA */ + modembits[3] = (brk << 4) | 2 | EA; /* Valid, EA */ ctrl = gsm_control_send(dlci->gsm, CMD_MSC, modembits, len + 1); if (ctrl == NULL) return -ENOMEM; @@ -2537,6 +2581,10 @@ static void gsm_dtr_rts(struct tty_port *port, int onoff) modem_tx |= TIOCM_DTR | TIOCM_RTS; else modem_tx &= ~(TIOCM_DTR | TIOCM_RTS); + + if (debug & 16) + gsm_print_modem(modem_tx); + if (modem_tx != dlci->modem_tx) { dlci->modem_tx = modem_tx; gsmtty_modem_update(dlci, 0); @@ -2556,6 +2604,7 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp) struct tty_port *port; unsigned int line = tty->index; unsigned int mux = line >> 6; + int ret; line = line & 0x3F; @@ -2583,8 +2632,18 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp) /* We could in theory open and close before we wait - eg if we get a DM straight back. This is ok as that will have caused a hangup */ set_bit(ASYNCB_INITIALIZED, &port->flags); + + if (debug & 16) + pr_debug("Request to open DLCI %d\n", dlci->addr); + /* Start sending off SABM messages */ gsm_dlci_begin_open(dlci); + + /* Wait for the modem to send a acknowledge to the open command */ + ret = wait_event_interruptible(gsm->event, dlci->state == DLCI_OPEN); + if (ret < 0) + return -ERESTARTSYS; + /* And wait for virtual carrier */ return tty_port_block_til_ready(port, tty, filp); } @@ -2612,8 +2671,13 @@ static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf, int len) { struct gsm_dlci *dlci = tty->driver_data; + int sent; + + if (debug & 16) + pr_debug("%d bytes for dlci %d\n", len, dlci->addr); + /* Stuff the bytes into the fifo queue */ - int sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock); + sent = kfifo_in_locked(dlci->fifo, buf, len, &dlci->lock); /* Need to kick the channel */ gsm_dlci_data_kick(dlci); return sent; @@ -2661,9 +2725,12 @@ static int gsmtty_tiocmset(struct tty_struct *tty, struct file *filp, struct gsm_dlci *dlci = tty->driver_data; unsigned int modem_tx = dlci->modem_tx; - modem_tx &= clear; + modem_tx &= ~clear; modem_tx |= set; + if (debug & 16) + gsm_print_modem(modem_tx); + if (modem_tx != dlci->modem_tx) { dlci->modem_tx = modem_tx; return gsmtty_modem_update(dlci, 0); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/