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)
Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 30 +++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)
Incorporated review comments from Jiri Slaby since v2:
- removed exlicit cast from enum to int
- removed unrelated removal of redundant assignment of gsm->encoding in
gsmld_open()
Link: https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index caa5c14ed57f..3fa859a29317 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 */
@@ -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 +2947,7 @@ static int gsmld_open(struct tty_struct *tty)
tty->receive_room = 65536;
/* Attach the initial passive connection */
- gsm->encoding = 1;
-
+ gsm->encoding = GSM_ADV_OPT;
gsmld_attach_gsm(tty, gsm);
timer_setup(&gsm->kick_timer, gsm_kick_timer, 0);
@@ -3345,7 +3349,7 @@ 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 +3378,7 @@ 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 +3402,8 @@ 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
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(+)
Incorporated review comments from Jiri Slaby since v2:
- changed (1 << n) to BIT(n) in the debug macro definitions
Link: https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index f8a8c4059907..6588b84eed96 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 BIT(2) /* Data transmission details. */
#define DBG_ERRORS BIT(3) /* Details for fail conditions. */
#define DBG_TTY BIT(4) /* Transmission statistics for DLCI TTYs. */
+#define DBG_PAYLOAD BIT(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
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(-)
Incorporated review comments from Jiri Slaby since v2:
- changed (1 << n) to BIT(n) in the debug macro definitions
Link: https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index e050d76385ba..f8a8c4059907 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 BIT(0) /* Data transmission dump. */
+#define DBG_CD_ON BIT(1) /* Always assume CD line on. */
+#define DBG_DATA BIT(2) /* Data transmission details. */
+#define DBG_ERRORS BIT(3) /* Details for fail conditions. */
+#define DBG_TTY BIT(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);
@@ -1766,7 +1773,7 @@ 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 */
@@ -1800,7 +1807,7 @@ 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)
@@ -1836,7 +1843,7 @@ 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;
@@ -1941,7 +1948,7 @@ 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", clen);
switch (dlci->adaption) {
/* Unsupported types */
@@ -2029,7 +2036,7 @@ 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__);
}
@@ -2163,7 +2170,7 @@ 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;
}
@@ -2789,7 +2796,7 @@ 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);
}
@@ -2876,7 +2883,7 @@ 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
From: Daniel Starke <[email protected]>
Move the content of gsm_control_transmit() to a new function
gsm_control_command() with a more generic signature and analog to
gsm_control_reply(). Use this within gsm_control_transmit().
This is needed to simplify upcoming functional additions.
Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)
Incorporated review comments from Jiri Slaby since v2:
- leading changed tab to space in function comment of gsm_control_command()
- made function parameter data to const in gsm_control_command()
- added extra line-feeds in gsm_control_command()
- kept signess and constness of other parameters in gsm_control_command()
to align with gsm_control_reply() as stated in the commit message;
possible changes here are subject to a different commit which should
keep the changes in alignment to the signature of gsm_control_reply()
Link: https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 9d0b4f79b65a..e050d76385ba 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1316,6 +1316,31 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci)
*/
+/**
+ * gsm_control_command - send a command frame to a control
+ * @gsm: gsm channel
+ * @cmd: the command to use
+ * @data: data to follow encoded info
+ * @dlen: length of data
+ *
+ * Encode up and queue a UI/UIH frame containing our command.
+ */
+static int gsm_control_command(struct gsm_mux *gsm, int cmd, const u8 *data,
+ int dlen)
+{
+ struct gsm_msg *msg = gsm_data_alloc(gsm, 0, dlen + 2, gsm->ftype);
+
+ if (msg == NULL)
+ return -ENOMEM;
+
+ msg->data[0] = (cmd << 1) | CR | EA; /* Set C/R */
+ msg->data[1] = (dlen << 1) | EA;
+ memcpy(msg->data + 2, data, dlen);
+ gsm_data_queue(gsm->dlci[0], msg);
+
+ return 0;
+}
+
/**
* gsm_control_reply - send a response frame to a control
* @gsm: gsm channel
@@ -1621,13 +1646,7 @@ 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 + 2, gsm->ftype);
- if (msg == NULL)
- return;
- msg->data[0] = (ctrl->cmd << 1) | CR | EA; /* command */
- msg->data[1] = (ctrl->len << 1) | EA;
- memcpy(msg->data + 2, ctrl->data, ctrl->len);
- gsm_data_queue(gsm->dlci[0], msg);
+ gsm_control_command(gsm, ctrl->cmd, ctrl->data, ctrl->len);
}
/**
--
2.34.1
From: Daniel Starke <[email protected]>
Add a macro which defines the possible number of virtual devices for n_gsm
to improve code readability.
Reviewed-by: Jiri Slaby <[email protected]>
Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
Added reviewed-by line since v2. No other changes done.
Link: https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 3fa859a29317..813363825e54 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
@@ -3749,7 +3752,7 @@ 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
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. See first link
below for reference.
Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Daniel Starke <[email protected]>
---
drivers/tty/n_gsm.c | 95 ++++++++++++++++++++++-----------------------
1 file changed, 47 insertions(+), 48 deletions(-)
Incorporated review comments from Jiri Slaby since v2:
- added link to test robot report
- added link to previously fixed error
- removed extra line-feeds in gsm_control_modem()
- removed unnecessary use of dp in gsm_dlci_command()
- changed clen and dlen to unsigned int in gsm_dlci_command()
- removed extra return in gsm_dlci_command()
Link: https://lore.kernel.org/all/[email protected]/
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 813363825e54..9d0b4f79b65a 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1418,18 +1418,12 @@ 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 +1432,20 @@ 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);
@@ -1921,11 +1920,10 @@ 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);
+ pr_debug("%d bytes for tty\n", clen);
switch (dlci->adaption) {
/* Unsupported types */
case 4: /* Packetised interruptible data */
@@ -1933,24 +1931,22 @@ 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 +1967,27 @@ 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;
- }
- }
+ unsigned int clen = 0;
+ unsigned int dlen;
+
+ /* read the command */
+ dlen = gsm_read_ea_val(&command, data, len);
+ len -= dlen;
+ data += dlen;
+
+ /* read any control data */
+ dlen = gsm_read_ea_val(&clen, data, len);
+ len -= dlen;
+ data += dlen;
+
+ /* 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);
}
/**
--
2.34.1
Is there any remaining issue with this patch series which prevents
a commit to the kernel tree?
Best regards,
Daniel Starke
On Wed, Sep 21, 2022 at 11:03:44AM +0000, Starke, Daniel wrote:
> Is there any remaining issue with this patch series which prevents
> a commit to the kernel tree?
I was hoping others would review them too...
I'll go do so now.
greg k-h