From c2f2f0000bb69f067fea12624272e6a58a811702 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Thu, 4 Nov 2010 15:17:03 +0000 Subject: n_gsm: Fix support for legacy encoding The mux supports several encoding schemes. Encoding 0 is a "not recommended" mode still sometimes used. This has now been tested with hardware that supports this mode, and found wanting. Fix the FCS handling in this mode and correct the state machine. Signed-off-by: Ken Mills Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 59 +++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 46 insertions(+), 13 deletions(-) (limited to 'drivers/tty/n_gsm.c') diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 04ef3ef0a42..5256087dd81 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -184,6 +184,9 @@ struct gsm_mux { #define GSM_DATA 5 #define GSM_FCS 6 #define GSM_OVERRUN 7 +#define GSM_LEN0 8 +#define GSM_LEN1 9 +#define GSM_SSOF 10 unsigned int len; unsigned int address; unsigned int count; @@ -191,6 +194,7 @@ struct gsm_mux { int encoding; u8 control; u8 fcs; + u8 received_fcs; u8 *txframe; /* TX framing buffer */ /* Methods for the receiver side */ @@ -1623,7 +1627,6 @@ static void gsm_dlci_free(struct gsm_dlci *dlci) kfree(dlci); } - /* * LAPBish link layer logic */ @@ -1648,6 +1651,8 @@ static void gsm_queue(struct gsm_mux *gsm) if ((gsm->control & ~PF) == UI) gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len); + /* generate final CRC with received FCS */ + gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs); if (gsm->fcs != GOOD_FCS) { gsm->bad_fcs++; if (debug & 4) @@ -1746,6 +1751,8 @@ invalid: static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) { + unsigned int len; + switch (gsm->state) { case GSM_SEARCH: /* SOF marker */ if (c == GSM0_SOF) { @@ -1754,8 +1761,8 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) gsm->len = 0; gsm->fcs = INIT_FCS; } - break; /* Address EA */ - case GSM_ADDRESS: + break; + case GSM_ADDRESS: /* Address EA */ gsm->fcs = gsm_fcs_add(gsm->fcs, c); if (gsm_read_ea(&gsm->address, c)) gsm->state = GSM_CONTROL; @@ -1763,9 +1770,9 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) case GSM_CONTROL: /* Control Byte */ gsm->fcs = gsm_fcs_add(gsm->fcs, c); gsm->control = c; - gsm->state = GSM_LEN; + gsm->state = GSM_LEN0; break; - case GSM_LEN: /* Length EA */ + case GSM_LEN0: /* Length EA */ gsm->fcs = gsm_fcs_add(gsm->fcs, c); if (gsm_read_ea(&gsm->len, c)) { if (gsm->len > gsm->mru) { @@ -1774,8 +1781,28 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) break; } gsm->count = 0; - gsm->state = GSM_DATA; + if (!gsm->len) + gsm->state = GSM_FCS; + else + gsm->state = GSM_DATA; + break; } + gsm->state = GSM_LEN1; + break; + case GSM_LEN1: + gsm->fcs = gsm_fcs_add(gsm->fcs, c); + len = c; + gsm->len |= len << 7; + if (gsm->len > gsm->mru) { + gsm->bad_size++; + gsm->state = GSM_SEARCH; + break; + } + gsm->count = 0; + if (!gsm->len) + gsm->state = GSM_FCS; + else + gsm->state = GSM_DATA; break; case GSM_DATA: /* Data */ gsm->buf[gsm->count++] = c; @@ -1783,16 +1810,25 @@ static void gsm0_receive(struct gsm_mux *gsm, unsigned char c) gsm->state = GSM_FCS; break; case GSM_FCS: /* FCS follows the packet */ - gsm->fcs = c; + gsm->received_fcs = c; + if (c == GSM0_SOF) { + gsm->state = GSM_SEARCH; + break; + } gsm_queue(gsm); - /* And then back for the next frame */ - gsm->state = GSM_SEARCH; + gsm->state = GSM_SSOF; + break; + case GSM_SSOF: + if (c == GSM0_SOF) { + gsm->state = GSM_SEARCH; + break; + } break; } } /** - * gsm0_receive - perform processing for non-transparency + * gsm1_receive - perform processing for non-transparency * @gsm: gsm data for this ldisc instance * @c: character * @@ -2032,9 +2068,6 @@ struct gsm_mux *gsm_alloc_mux(void) } EXPORT_SYMBOL_GPL(gsm_alloc_mux); - - - /** * gsmld_output - write to link * @gsm: our mux -- cgit v1.2.3-70-g09d2 From 5f9a31d63105c3e88bd6d026e7bc53f02a5ac042 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Thu, 4 Nov 2010 15:17:27 +0000 Subject: n_gsm: clean up printks [Original From Ken Mills but I redid it using pr_ helpers instead] Also fix up coding style, there are two warnings left but that is where the CodingStyle tools blow up because they cannot handle if (blah) { foo } else switch (x) { case 1: } Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_gsm.c | 154 +++++++++++++++++++++++++++------------------------- 1 file changed, 81 insertions(+), 73 deletions(-) (limited to 'drivers/tty/n_gsm.c') diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 5256087dd81..11a25fa7d76 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -19,7 +19,7 @@ * * TO DO: * Mostly done: ioctls for setting modes/timing - * Partly done: hooks so you can pull off frames to non tty devs + * Partly done: hooks so you can pull off frames to non tty devs * Restart DLCI 0 when it closes ? * Test basic encoding * Improve the tx engine @@ -73,8 +73,10 @@ module_param(debug, int, 0600); #define T2 (2 * HZ) #endif -/* Semi-arbitary buffer size limits. 0710 is normally run with 32-64 byte - limits so this is plenty */ +/* + * 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 @@ -290,7 +292,7 @@ static spinlock_t gsm_mux_lock; #define MDM_DV 0x40 #define GSM0_SOF 0xF9 -#define GSM1_SOF 0x7E +#define GSM1_SOF 0x7E #define GSM1_ESCAPE 0x7D #define GSM1_ESCAPE_BITS 0x20 #define XON 0x11 @@ -433,61 +435,63 @@ static void gsm_print_packet(const char *hdr, int addr, int cr, if (!(debug & 1)) return; - printk(KERN_INFO "%s %d) %c: ", hdr, addr, "RC"[cr]); + pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]); switch (control & ~PF) { case SABM: - printk(KERN_CONT "SABM"); + pr_cont("SABM"); break; case UA: - printk(KERN_CONT "UA"); + pr_cont("UA"); break; case DISC: - printk(KERN_CONT "DISC"); + pr_cont("DISC"); break; case DM: - printk(KERN_CONT "DM"); + pr_cont("DM"); break; case UI: - printk(KERN_CONT "UI"); + pr_cont("UI"); break; case UIH: - printk(KERN_CONT "UIH"); + pr_cont("UIH"); break; default: if (!(control & 0x01)) { - printk(KERN_CONT "I N(S)%d N(R)%d", - (control & 0x0E) >> 1, (control & 0xE)>> 5); + pr_cont("I N(S)%d N(R)%d", + (control & 0x0E) >> 1, (control & 0xE) >> 5); } else switch (control & 0x0F) { - case RR: - printk("RR(%d)", (control & 0xE0) >> 5); - break; - case RNR: - printk("RNR(%d)", (control & 0xE0) >> 5); - break; - case REJ: - printk("REJ(%d)", (control & 0xE0) >> 5); - break; - default: - printk(KERN_CONT "[%02X]", control); + case RR: + pr_cont("RR(%d)", (control & 0xE0) >> 5); + break; + case RNR: + pr_cont("RNR(%d)", (control & 0xE0) >> 5); + break; + case REJ: + pr_cont("REJ(%d)", (control & 0xE0) >> 5); + break; + default: + pr_cont("[%02X]", control); } } if (control & PF) - printk(KERN_CONT "(P)"); + pr_cont("(P)"); else - printk(KERN_CONT "(F)"); + pr_cont("(F)"); if (dlen) { int ct = 0; while (dlen--) { - if (ct % 8 == 0) - printk(KERN_CONT "\n "); - printk(KERN_CONT "%02X ", *data++); + if (ct % 8 == 0) { + pr_cont("\n"); + pr_debug(" "); + } + pr_cont("%02X ", *data++); ct++; } } - printk(KERN_CONT "\n"); + pr_cont("\n"); } @@ -526,11 +530,13 @@ static void hex_packet(const unsigned char *p, int len) { int i; for (i = 0; i < len; i++) { - if (i && (i % 16) == 0) - printk("\n"); - printk("%02X ", *p++); + if (i && (i % 16) == 0) { + pr_cont("\n"); + pr_debug(""); + } + pr_cont("%02X ", *p++); } - printk("\n"); + pr_cont("\n"); } /** @@ -680,7 +686,7 @@ static void gsm_data_kick(struct gsm_mux *gsm) } if (debug & 4) { - printk("gsm_data_kick: \n"); + pr_debug("gsm_data_kick:\n"); hex_packet(gsm->txframe, len); } @@ -1233,7 +1239,7 @@ static void gsm_control_response(struct gsm_mux *gsm, unsigned int command, } /** - * gsm_control_transmit - send control packet + * gsm_control_transmit - send control packet * @gsm: gsm mux * @ctrl: frame to send * @@ -1363,7 +1369,7 @@ static void gsm_dlci_close(struct gsm_dlci *dlci) { del_timer(&dlci->t1); if (debug & 8) - printk("DLCI %d goes closed.\n", dlci->addr); + pr_debug("DLCI %d goes closed.\n", dlci->addr); dlci->state = DLCI_CLOSED; if (dlci->addr != 0) { struct tty_struct *tty = tty_port_tty_get(&dlci->port); @@ -1394,7 +1400,7 @@ static void gsm_dlci_open(struct gsm_dlci *dlci) /* This will let a tty open continue */ dlci->state = DLCI_OPEN; if (debug & 8) - printk("DLCI %d goes open.\n", dlci->addr); + pr_debug("DLCI %d goes open.\n", dlci->addr); wake_up(&dlci->gsm->event); } @@ -1496,29 +1502,29 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len) unsigned int modem = 0; if (debug & 16) - printk("%d bytes for tty %p\n", len, tty); + pr_debug("%d bytes for tty %p\n", len, tty); if (tty) { switch (dlci->adaption) { - /* Unsupported types */ - /* Packetised interruptible data */ - case 4: - break; - /* Packetised uininterruptible voice/data */ - case 3: - break; - /* Asynchronous serial with line state in each frame */ - case 2: - while (gsm_read_ea(&modem, *data++) == 0) { - len--; - if (len == 0) - return; - } - gsm_process_modem(tty, dlci, modem); - /* Line state will go via DLCI 0 controls only */ - case 1: - default: - tty_insert_flip_string(tty, data, len); - tty_flip_buffer_push(tty); + /* Unsupported types */ + /* Packetised interruptible data */ + case 4: + break; + /* Packetised uininterruptible voice/data */ + case 3: + break; + /* Asynchronous serial with line state in each frame */ + case 2: + while (gsm_read_ea(&modem, *data++) == 0) { + len--; + if (len == 0) + return; + } + gsm_process_modem(tty, dlci, modem); + /* Line state will go via DLCI 0 controls only */ + case 1: + default: + tty_insert_flip_string(tty, data, len); + tty_flip_buffer_push(tty); } tty_kref_put(tty); } @@ -1656,7 +1662,7 @@ static void gsm_queue(struct gsm_mux *gsm) if (gsm->fcs != GOOD_FCS) { gsm->bad_fcs++; if (debug & 4) - printk("BAD FCS %02x\n", gsm->fcs); + pr_debug("BAD FCS %02x\n", gsm->fcs); return; } address = gsm->address >> 1; @@ -1890,7 +1896,7 @@ static void gsm1_receive(struct gsm_mux *gsm, unsigned char c) gsm->state = GSM_DATA; break; case GSM_DATA: /* Data */ - if (gsm->count > gsm->mru ) { /* Allow one for the FCS */ + if (gsm->count > gsm->mru) { /* Allow one for the FCS */ gsm->state = GSM_OVERRUN; gsm->bad_size++; } else @@ -2085,7 +2091,7 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len) return -ENOSPC; } if (debug & 4) { - printk("-->%d bytes out\n", len); + pr_debug("-->%d bytes out\n", len); hex_packet(data, len); } gsm->tty->ops->write(gsm->tty, data, len); @@ -2142,7 +2148,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, char flags; if (debug & 4) { - printk("Inbytes %dd\n", count); + pr_debug("Inbytes %dd\n", count); hex_packet(cp, count); } @@ -2159,7 +2165,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, gsm->error(gsm, *dp, flags); break; default: - printk(KERN_ERR "%s: unknown flag %d\n", + WARN_ONCE("%s: unknown flag %d\n", tty_name(tty, buf), flags); break; } @@ -2354,7 +2360,7 @@ static int gsmld_config(struct tty_struct *tty, struct gsm_mux *gsm, int need_restart = 0; /* Stuff we don't support yet - UI or I frame transport, windowing */ - if ((c->adaption !=1 && c->adaption != 2) || c->k) + if ((c->adaption != 1 && c->adaption != 2) || c->k) return -EOPNOTSUPP; /* Check the MRU/MTU range looks sane */ if (c->mru > MAX_MRU || c->mtu > MAX_MTU || c->mru < 8 || c->mtu < 8) @@ -2448,7 +2454,7 @@ static int gsmld_ioctl(struct tty_struct *tty, struct file *file, c.i = 1; else c.i = 2; - printk("Ftype %d i %d\n", gsm->ftype, c.i); + pr_debug("Ftype %d i %d\n", gsm->ftype, c.i); c.mru = gsm->mru; c.mtu = gsm->mtu; c.k = 0; @@ -2742,14 +2748,15 @@ static int __init gsm_init(void) /* Fill in our line protocol discipline, and register it */ int status = tty_register_ldisc(N_GSM0710, &tty_ldisc_packet); if (status != 0) { - printk(KERN_ERR "n_gsm: can't register line discipline (err = %d)\n", status); + pr_err("n_gsm: can't register line discipline (err = %d)\n", + status); return status; } gsm_tty_driver = alloc_tty_driver(256); if (!gsm_tty_driver) { tty_unregister_ldisc(N_GSM0710); - printk(KERN_ERR "gsm_init: tty allocation failed.\n"); + pr_err("gsm_init: tty allocation failed.\n"); return -EINVAL; } gsm_tty_driver->owner = THIS_MODULE; @@ -2760,7 +2767,7 @@ static int __init gsm_init(void) gsm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; gsm_tty_driver->subtype = SERIAL_TYPE_NORMAL; gsm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV - | TTY_DRIVER_HARDWARE_BREAK; + | TTY_DRIVER_HARDWARE_BREAK; gsm_tty_driver->init_termios = tty_std_termios; /* Fixme */ gsm_tty_driver->init_termios.c_lflag &= ~ECHO; @@ -2771,10 +2778,11 @@ static int __init gsm_init(void) if (tty_register_driver(gsm_tty_driver)) { put_tty_driver(gsm_tty_driver); tty_unregister_ldisc(N_GSM0710); - printk(KERN_ERR "gsm_init: tty registration failed.\n"); + pr_err("gsm_init: tty registration failed.\n"); return -EBUSY; } - printk(KERN_INFO "gsm_init: loaded as %d,%d.\n", gsm_tty_driver->major, gsm_tty_driver->minor_start); + pr_debug("gsm_init: loaded as %d,%d.\n", + gsm_tty_driver->major, gsm_tty_driver->minor_start); return 0; } @@ -2782,10 +2790,10 @@ static void __exit gsm_exit(void) { int status = tty_unregister_ldisc(N_GSM0710); if (status != 0) - printk(KERN_ERR "n_gsm: can't unregister line discipline (err = %d)\n", status); + pr_err("n_gsm: can't unregister line discipline (err = %d)\n", + status); tty_unregister_driver(gsm_tty_driver); put_tty_driver(gsm_tty_driver); - printk(KERN_INFO "gsm_init: unloaded.\n"); } module_init(gsm_init); -- cgit v1.2.3-70-g09d2