2022-08-22 07:28:38

by D. Starke

[permalink] [raw]
Subject: [PATCH 1/6] tty: n_gsm: add enumeration for gsm encodings

From: Daniel Starke <[email protected]>

Add an enumeration for the gsm mux encoding types to improve code
readability and to avoid invalid values. Only two values are defined by the
standard:
- basic option mode
- advanced option mode (uses ISO HDLC standard transparency mechanism)

Also remove redundant configuration in gsmld_open(). The same value is
already set in gsm_alloc_mux() which is also called in gsmld_open().

Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 31 +++++++++++++++++--------------
1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index caa5c14ed57f..5bf09d129357 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -184,6 +184,11 @@ struct gsm_control {
int error; /* Error if any */
};

+enum gsm_encoding {
+ GSM_BASIC_OPT,
+ GSM_ADV_OPT,
+};
+
enum gsm_mux_state {
GSM_SEARCH,
GSM_START,
@@ -230,7 +235,7 @@ struct gsm_mux {
unsigned int address;
unsigned int count;
bool escape;
- int encoding;
+ enum gsm_encoding encoding;
u8 control;
u8 fcs;
u8 *txframe; /* TX framing buffer */
@@ -694,7 +699,7 @@ static int gsm_send(struct gsm_mux *gsm, int addr, int cr, int control)
*dp++ = (addr << 2) | (ocr << 1) | EA;
*dp++ = control;

- if (gsm->encoding == 0)
+ if (gsm->encoding == GSM_BASIC_OPT)
*dp++ = EA; /* Length of data = 0 */

*dp = 0xFF - gsm_fcs_add_block(INIT_FCS, msg->data, dp - msg->data);
@@ -813,7 +818,7 @@ static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg)
int len, ret;


- if (gsm->encoding == 0) {
+ if (gsm->encoding == GSM_BASIC_OPT) {
gsm->txframe[0] = GSM0_SOF;
memcpy(gsm->txframe + 1, msg->data, msg->len);
gsm->txframe[msg->len + 1] = GSM0_SOF;
@@ -965,7 +970,7 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)
u8 *fcs = dp + msg->len;

/* Fill in the header */
- if (gsm->encoding == 0) {
+ if (gsm->encoding == GSM_BASIC_OPT) {
if (msg->len < 128)
*--dp = (msg->len << 1) | EA;
else {
@@ -2508,7 +2513,7 @@ static int gsm_activate_mux(struct gsm_mux *gsm)
spin_lock_init(&gsm->control_lock);
spin_lock_init(&gsm->tx_lock);

- if (gsm->encoding == 0)
+ if (gsm->encoding == GSM_BASIC_OPT)
gsm->receive = gsm0_receive;
else
gsm->receive = gsm1_receive;
@@ -2618,7 +2623,7 @@ static struct gsm_mux *gsm_alloc_mux(void)
gsm->n2 = N2;
gsm->ftype = UIH;
gsm->adaption = 1;
- gsm->encoding = 1;
+ gsm->encoding = GSM_ADV_OPT;
gsm->mru = 64; /* Default to encoding 1 so these should be 64 */
gsm->mtu = 64;
gsm->dead = true; /* Avoid early tty opens */
@@ -2651,7 +2656,7 @@ static void gsm_copy_config_values(struct gsm_mux *gsm,
{
memset(c, 0, sizeof(*c));
c->adaption = gsm->adaption;
- c->encapsulation = gsm->encoding;
+ c->encapsulation = (int)gsm->encoding;
c->initiator = gsm->initiator;
c->t1 = gsm->t1;
c->t2 = gsm->t2;
@@ -2719,7 +2724,7 @@ static int gsm_config(struct gsm_mux *gsm, struct gsm_config *c)
gsm->initiator = c->initiator;
gsm->mru = c->mru;
gsm->mtu = c->mtu;
- gsm->encoding = c->encapsulation;
+ gsm->encoding = c->encapsulation ? GSM_ADV_OPT : GSM_BASIC_OPT;
gsm->adaption = c->adaption;
gsm->n2 = c->n2;

@@ -2942,8 +2947,6 @@ static int gsmld_open(struct tty_struct *tty)
tty->receive_room = 65536;

/* Attach the initial passive connection */
- gsm->encoding = 1;
-
gsmld_attach_gsm(tty, gsm);

timer_setup(&gsm->kick_timer, gsm_kick_timer, 0);
@@ -3345,7 +3348,7 @@ static int gsm_modem_upd_via_msc(struct gsm_dlci *dlci, u8 brk)
struct gsm_control *ctrl;
int len = 2;

- if (dlci->gsm->encoding != 0)
+ if (dlci->gsm->encoding != GSM_BASIC_OPT)
return 0;

modembits[0] = (dlci->addr << 2) | 2 | EA; /* DLCI, Valid, EA */
@@ -3374,7 +3377,7 @@ static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk)
/* Send convergence layer type 2 empty data frame. */
gsm_modem_upd_via_data(dlci, brk);
return 0;
- } else if (dlci->gsm->encoding == 0) {
+ } else if (dlci->gsm->encoding == GSM_BASIC_OPT) {
/* Send as MSC control message. */
return gsm_modem_upd_via_msc(dlci, brk);
}
@@ -3398,8 +3401,8 @@ static int gsm_carrier_raised(struct tty_port *port)
* Basic mode with control channel in ADM mode may not respond
* to CMD_MSC at all and modem_rx is empty.
*/
- if (gsm->encoding == 0 && gsm->dlci[0]->mode == DLCI_MODE_ADM &&
- !dlci->modem_rx)
+ if (gsm->encoding == GSM_BASIC_OPT &&
+ gsm->dlci[0]->mode == DLCI_MODE_ADM && !dlci->modem_rx)
return 1;

return dlci->modem_rx & TIOCM_CD;
--
2.34.1


2022-08-22 07:28:52

by D. Starke

[permalink] [raw]
Subject: [PATCH 2/6] tty: n_gsm: name gsm tty device minors

From: Daniel Starke <[email protected]>

Add a macro which defines the possible number of virtual devices for n_gsm
to improve code readability.

Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 5bf09d129357..ed399d57b197 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -164,6 +164,9 @@ struct gsm_dlci {
struct net_device *net; /* network interface, if created */
};

+/* Total number of supported devices */
+#define GSM_TTY_MINORS 256
+
/* DLCI 0, 62/63 are special or reserved see gsmtty_open */

#define NUM_DLCI 64
@@ -3748,7 +3751,7 @@ static int __init gsm_init(void)
return status;
}

- gsm_tty_driver = tty_alloc_driver(256, TTY_DRIVER_REAL_RAW |
+ gsm_tty_driver = tty_alloc_driver(GSM_TTY_MINORS, TTY_DRIVER_REAL_RAW |
TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_HARDWARE_BREAK);
if (IS_ERR(gsm_tty_driver)) {
pr_err("gsm_init: tty allocation failed.\n");
--
2.34.1

2022-08-22 07:39:58

by D. Starke

[permalink] [raw]
Subject: [PATCH 6/6] tty: n_gsm: add debug bit for user payload

From: Daniel Starke <[email protected]>

A debug bit to output a complete transmission dump exists. Sometimes only
the user frames are relevant. Add an additional bit which limits the
transmission dump output to user data frames if set.

Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e8f10a5f0a8a..676034fb1190 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -69,6 +69,7 @@ module_param(debug, int, 0600);
#define DBG_DATA (1 << 2) /* Data transmission details. */
#define DBG_ERRORS (1 << 3) /* Details for fail conditions. */
#define DBG_TTY (1 << 4) /* Transmission statistics for DLCI TTYs. */
+#define DBG_PAYLOAD (1 << 5) /* Limits DBG_DUMP to payload frames. */

/* Defaults: these are from the specification */

@@ -598,6 +599,10 @@ static void gsm_print_packet(const char *hdr, int addr, int cr,
{
if (!(debug & DBG_DUMP))
return;
+ /* Only show user payload frames if debug & DBG_PAYLOAD */
+ if (!(debug & DBG_PAYLOAD) && addr != 0)
+ if ((control & ~PF) == UI || (control & ~PF) == UIH)
+ return;

pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]);

--
2.34.1

2022-08-22 07:43:51

by D. Starke

[permalink] [raw]
Subject: [PATCH 5/6] tty: n_gsm: name the debug bits

From: Daniel Starke <[email protected]>

Introduce defines to name the various debug bits used within the code to
improve readability and to make its specific use clear.

Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 31 +++++++++++++++++++------------
1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 71599198eb6d..e8f10a5f0a8a 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -63,6 +63,13 @@
static int debug;
module_param(debug, int, 0600);

+/* Module debug bits */
+#define DBG_DUMP (1 << 0) /* Data transmission dump. */
+#define DBG_CD_ON (1 << 1) /* Always assume CD line on. */
+#define DBG_DATA (1 << 2) /* Data transmission details. */
+#define DBG_ERRORS (1 << 3) /* Details for fail conditions. */
+#define DBG_TTY (1 << 4) /* Transmission statistics for DLCI TTYs. */
+
/* Defaults: these are from the specification */

#define T1 10 /* 100mS */
@@ -535,7 +542,7 @@ static int gsm_register_devices(struct tty_driver *driver, unsigned int index)
*/
dev = tty_register_device(gsm_tty_driver, base + i, NULL);
if (IS_ERR(dev)) {
- if (debug & 8)
+ if (debug & DBG_ERRORS)
pr_info("%s failed to register device minor %u",
__func__, base + i);
for (i--; i >= 1; i--)
@@ -589,7 +596,7 @@ static void gsm_unregister_devices(struct tty_driver *driver,
static void gsm_print_packet(const char *hdr, int addr, int cr,
u8 control, const u8 *data, int dlen)
{
- if (!(debug & 1))
+ if (!(debug & DBG_DUMP))
return;

pr_info("%s %d) %c: ", hdr, addr, "RC"[cr]);
@@ -833,7 +840,7 @@ static int gsm_send_packet(struct gsm_mux *gsm, struct gsm_msg *msg)
len += 2;
}

- if (debug & 4)
+ if (debug & DBG_DATA)
gsm_hex_dump_bytes(__func__, gsm->txframe, len);
gsm_print_packet("-->", msg->addr, gsm->initiator, msg->ctrl, msg->data,
msg->len);
@@ -1765,7 +1772,7 @@ static int gsm_control_wait(struct gsm_mux *gsm, struct gsm_control *control)
static void gsm_dlci_close(struct gsm_dlci *dlci)
{
del_timer(&dlci->t1);
- if (debug & 8)
+ if (debug & DBG_ERRORS)
pr_debug("DLCI %d goes closed.\n", dlci->addr);
dlci->state = DLCI_CLOSED;
/* Prevent us from sending data before the link is up again */
@@ -1799,7 +1806,7 @@ static void gsm_dlci_open(struct gsm_dlci *dlci)
/* This will let a tty open continue */
dlci->state = DLCI_OPEN;
dlci->constipated = false;
- if (debug & 8)
+ if (debug & DBG_ERRORS)
pr_debug("DLCI %d goes open.\n", dlci->addr);
/* Send current modem state */
if (dlci->addr)
@@ -1835,7 +1842,7 @@ static void gsm_dlci_t1(struct timer_list *t)
gsm_command(dlci->gsm, dlci->addr, SABM|PF);
mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
} else if (!dlci->addr && gsm->control == (DM | PF)) {
- if (debug & 8)
+ if (debug & DBG_ERRORS)
pr_info("DLCI %d opening in ADM mode.\n",
dlci->addr);
dlci->mode = DLCI_MODE_ADM;
@@ -1940,7 +1947,7 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
unsigned int modem = 0;
int len;

- if (debug & 16)
+ if (debug & DBG_TTY)
pr_debug("%d bytes for tty\n", len);
switch (dlci->adaption) {
/* Unsupported types */
@@ -2030,7 +2037,7 @@ static void gsm_kick_timer(struct timer_list *t)
sent = gsm_dlci_data_sweep(gsm);
spin_unlock_irqrestore(&gsm->tx_lock, flags);

- if (sent && debug & 4)
+ if (sent && debug & DBG_DATA)
pr_info("%s TX queue stalled\n", __func__);
}

@@ -2164,7 +2171,7 @@ static void gsm_queue(struct gsm_mux *gsm)

if (gsm->fcs != GOOD_FCS) {
gsm->bad_fcs++;
- if (debug & 4)
+ if (debug & DBG_DATA)
pr_debug("BAD FCS %02x\n", gsm->fcs);
return;
}
@@ -2790,7 +2797,7 @@ static int gsmld_output(struct gsm_mux *gsm, u8 *data, int len)
set_bit(TTY_DO_WRITE_WAKEUP, &gsm->tty->flags);
return -ENOSPC;
}
- if (debug & 4)
+ if (debug & DBG_DATA)
gsm_hex_dump_bytes(__func__, data, len);
return gsm->tty->ops->write(gsm->tty, data, len);
}
@@ -2877,7 +2884,7 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
struct gsm_mux *gsm = tty->disc_data;
char flags = TTY_NORMAL;

- if (debug & 4)
+ if (debug & DBG_DATA)
gsm_hex_dump_bytes(__func__, cp, count);

for (; count; count--, cp++) {
@@ -3416,7 +3423,7 @@ static int gsm_carrier_raised(struct tty_port *port)
/* Not yet open so no carrier info */
if (dlci->state != DLCI_OPEN)
return 0;
- if (debug & 2)
+ if (debug & DBG_CD_ON)
return 1;

/*
--
2.34.1

2022-08-22 07:52:09

by D. Starke

[permalink] [raw]
Subject: [PATCH 3/6] tty: n_gsm: replace use of gsm_read_ea() with gsm_read_ea_val()

From: Daniel Starke <[email protected]>

Replace the use of gsm_read_ea() with gsm_read_ea_val() where applicable to
improve code readability and avoid errors like in the past.

Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 97 +++++++++++++++++++++++----------------------
1 file changed, 50 insertions(+), 47 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index ed399d57b197..c87525b70e81 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1418,18 +1418,13 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen)
unsigned int modem = 0;
struct gsm_dlci *dlci;
int len = clen;
- int slen;
+ int cl = clen;
const u8 *dp = data;
struct tty_struct *tty;

- while (gsm_read_ea(&addr, *dp++) == 0) {
- len--;
- if (len == 0)
- return;
- }
- /* Must be at least one byte following the EA */
- len--;
- if (len <= 0)
+ len = gsm_read_ea_val(&addr, data, cl);
+
+ if (len < 1)
return;

addr >>= 1;
@@ -1438,15 +1433,21 @@ 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)
- return;
- }
- len--;
+ /* Must be at least one byte following the EA */
+ if ((cl - len) < 1)
+ return;
+
+ dp += len;
+ cl -= len;
+
+ /* get the modem status */
+ len = gsm_read_ea_val(&modem, dp, cl);
+
+ if (len < 1)
+ return;
+
tty = tty_port_tty_get(&dlci->port);
- gsm_process_modem(tty, dlci, modem, slen - len);
+ gsm_process_modem(tty, dlci, modem, cl);
if (tty) {
tty_wakeup(tty);
tty_kref_put(tty);
@@ -1921,8 +1922,7 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
struct tty_port *port = &dlci->port;
struct tty_struct *tty;
unsigned int modem = 0;
- int len = clen;
- int slen = 0;
+ int len;

if (debug & 16)
pr_debug("%d bytes for tty\n", len);
@@ -1933,24 +1933,22 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
case 3: /* Packetised uininterruptible voice/data */
break;
case 2: /* Asynchronous serial with line state in each frame */
- while (gsm_read_ea(&modem, *data++) == 0) {
- len--;
- slen++;
- if (len == 0)
- return;
- }
- len--;
- slen++;
+ len = gsm_read_ea_val(&modem, data, clen);
+ if (len < 1)
+ return;
tty = tty_port_tty_get(port);
if (tty) {
- gsm_process_modem(tty, dlci, modem, slen);
+ gsm_process_modem(tty, dlci, modem, len);
tty_wakeup(tty);
tty_kref_put(tty);
}
+ /* Skip processed modem data */
+ data += len;
+ clen -= len;
fallthrough;
case 1: /* Line state will go via DLCI 0 controls only */
default:
- tty_insert_flip_string(port, data, len);
+ tty_insert_flip_string(port, data, clen);
tty_flip_buffer_push(port);
}
}
@@ -1971,24 +1969,29 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len)
{
/* See what command is involved */
unsigned int command = 0;
- while (len-- > 0) {
- if (gsm_read_ea(&command, *data++) == 1) {
- int clen = *data++;
- len--;
- /* FIXME: this is properly an EA */
- clen >>= 1;
- /* Malformed command ? */
- if (clen > len)
- return;
- if (command & 1)
- gsm_control_message(dlci->gsm, command,
- data, clen);
- else
- gsm_control_response(dlci->gsm, command,
- data, clen);
- return;
- }
- }
+ const u8 *dp = data;
+ int clen = 0;
+ int dlen;
+
+ /* read the command */
+ dlen = gsm_read_ea_val(&command, dp, len);
+ len -= dlen;
+ dp += dlen;
+
+ /* read any control data */
+ dlen = gsm_read_ea_val(&clen, dp, len);
+ len -= dlen;
+ dp += dlen;
+
+ /* Malformed command? */
+ if (clen > len)
+ return;
+
+ if (command & 1)
+ gsm_control_message(dlci->gsm, command, dp, clen);
+ else
+ gsm_control_response(dlci->gsm, command, dp, clen);
+ return;
}

/**
--
2.34.1

2022-08-22 14:09:10

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH 3/6] tty: n_gsm: replace use of gsm_read_ea() with gsm_read_ea_val()

Hi Starke",

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tty/tty-testing]
[also build test WARNING on linus/master v6.0-rc2 next-20220822]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/D-Starke/tty-n_gsm-add-enumeration-for-gsm-encodings/20220822-152532
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
config: i386-randconfig-a003-20220822 (https://download.01.org/0day-ci/archive/20220822/[email protected]/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/66ec0ad14dba76f793ec89ecdc7e6d7b3c550873
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review D-Starke/tty-n_gsm-add-enumeration-for-gsm-encodings/20220822-152532
git checkout 66ec0ad14dba76f793ec89ecdc7e6d7b3c550873
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/tty/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>

All warnings (new ones prefixed by >>):

>> drivers/tty/n_gsm.c:1928:34: warning: variable 'len' is uninitialized when used here [-Wuninitialized]
pr_debug("%d bytes for tty\n", len);
^~~
include/linux/printk.h:588:26: note: expanded from macro 'pr_debug'
dynamic_pr_debug(fmt, ##__VA_ARGS__)
^~~~~~~~~~~
include/linux/dynamic_debug.h:163:22: note: expanded from macro 'dynamic_pr_debug'
pr_fmt(fmt), ##__VA_ARGS__)
^~~~~~~~~~~
include/linux/dynamic_debug.h:152:56: note: expanded from macro '_dynamic_func_call'
__dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
^~~~~~~~~~~
include/linux/dynamic_debug.h:134:15: note: expanded from macro '__dynamic_func_call'
func(&id, ##__VA_ARGS__); \
^~~~~~~~~~~
drivers/tty/n_gsm.c:1925:9: note: initialize the variable 'len' to silence this warning
int len;
^
= 0
1 warning generated.


vim +/len +1928 drivers/tty/n_gsm.c

e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1907
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1908 /**
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1909 * gsm_dlci_data - data arrived
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1910 * @dlci: channel
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1911 * @data: block of bytes received
724ac070ffc7a1 drivers/tty/n_gsm.c Jiri Slaby 2020-08-18 1912 * @clen: length of received block
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1913 *
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1914 * A UI or UIH frame has arrived which contains data for a channel
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1915 * other than the control channel. If the relevant virtual tty is
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1916 * open we shovel the bits down it, if not we drop them.
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1917 */
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1918
4feb7a4a124444 drivers/tty/n_gsm.c Tony Lindgren 2019-01-13 1919 static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1920 {
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1921 /* krefs .. */
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1922 struct tty_port *port = &dlci->port;
2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1923 struct tty_struct *tty;
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1924 unsigned int modem = 0;
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1925 int len;
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1926
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1927 if (debug & 16)
2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 @1928 pr_debug("%d bytes for tty\n", len);
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1929 switch (dlci->adaption) {
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1930 /* Unsupported types */
3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1931 case 4: /* Packetised interruptible data */
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1932 break;
3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1933 case 3: /* Packetised uininterruptible voice/data */
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1934 break;
3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1935 case 2: /* Asynchronous serial with line state in each frame */
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1936 len = gsm_read_ea_val(&modem, data, clen);
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1937 if (len < 1)
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1938 return;
2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1939 tty = tty_port_tty_get(port);
2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1940 if (tty) {
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1941 gsm_process_modem(tty, dlci, modem, len);
1adf6fee58ca25 drivers/tty/n_gsm.c Daniel Starke 2022-04-14 1942 tty_wakeup(tty);
2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1943 tty_kref_put(tty);
2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1944 }
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1945 /* Skip processed modem data */
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1946 data += len;
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1947 clen -= len;
df561f6688fef7 drivers/tty/n_gsm.c Gustavo A. R. Silva 2020-08-23 1948 fallthrough;
3e913eebdfbb56 drivers/tty/n_gsm.c Gustavo A. R. Silva 2019-02-25 1949 case 1: /* Line state will go via DLCI 0 controls only */
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1950 default:
66ec0ad14dba76 drivers/tty/n_gsm.c Daniel Starke 2022-08-22 1951 tty_insert_flip_string(port, data, clen);
2e124b4a390ca8 drivers/tty/n_gsm.c Jiri Slaby 2013-01-03 1952 tty_flip_buffer_push(port);
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1953 }
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1954 }
e1eaea46bb4020 drivers/char/n_gsm.c Alan Cox 2010-03-26 1955

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