tty: n_gsm: Fixed logic to decode break signal from modem status
The modem status can be one or 2 octets and contains the V.24 signals
and in the 2 octet case also the break signal.
We were improperly decoding the break signal from the modem in the
2 octet case.
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 09e8c7d..7290394 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -984,10 +984,22 @@
*/
static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
- u32 modem)
+ u32 modem, int clen)
{
int mlines = 0;
- u8 brk = modem >> 6;
+ u8 brk = 0;
+
+ /* 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. */
+
+ if (clen == 2)
+ modem = modem & 0x7f;
+ else {
+ brk = modem & 0x7f;
+ modem = (modem >> 7) & 0x7f;
+ };
/* Flow control/ready to communicate */
if (modem & MDM_FC) {
@@ -1061,7 +1073,7 @@
return;
}
tty = tty_port_tty_get(&dlci->port);
- gsm_process_modem(tty, dlci, modem);
+ gsm_process_modem(tty, dlci, modem, clen);
if (tty) {
tty_wakeup(tty);
tty_kref_put(tty);
@@ -1482,12 +1494,13 @@
* open we shovel the bits down it, if not we drop them.
*/
-static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len)
+static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int clen)
{
/* krefs .. */
struct tty_port *port = &dlci->port;
struct tty_struct *tty = tty_port_tty_get(port);
unsigned int modem = 0;
+ int len = clen;
if (debug & 16)
pr_debug("%d bytes for tty %p\n", len, tty);
@@ -1507,7 +1520,7 @@
if (len == 0)
return;
}
- gsm_process_modem(tty, dlci, modem);
+ gsm_process_modem(tty, dlci, modem, clen);
/* Line state will go via DLCI 0 controls only */
case 1:
default: