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path: root/drivers/tty/n_gsm.c
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Diffstat (limited to 'drivers/tty/n_gsm.c')
-rw-r--r--drivers/tty/n_gsm.c33
1 files changed, 32 insertions, 1 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index c6c8ee9cbdc3..58ea30fd6576 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1536,6 +1536,7 @@ static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
if (brk & 0x01)
tty_insert_flip_char(&dlci->port, 0, TTY_BREAK);
dlci->modem_rx = mlines;
+ wake_up_interruptible(&dlci->gsm->event);
}
/**
@@ -2071,7 +2072,7 @@ static void gsm_dlci_close(struct gsm_dlci *dlci)
/* A DLCI 0 close is a MUX termination so we need to kick that
back to userspace somehow */
gsm_dlci_data_kick(dlci);
- wake_up(&dlci->gsm->event);
+ wake_up_all(&dlci->gsm->event);
}
/**
@@ -2272,6 +2273,7 @@ static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
dlci->state = DLCI_CLOSING;
gsm_command(dlci->gsm, dlci->addr, DISC|PF);
mod_timer(&dlci->t1, jiffies + gsm->t1 * HZ / 100);
+ wake_up_interruptible(&gsm->event);
}
/**
@@ -3775,6 +3777,33 @@ static int gsm_modem_update(struct gsm_dlci *dlci, u8 brk)
return -EPROTONOSUPPORT;
}
+/**
+ * gsm_wait_modem_change - wait for modem status line change
+ * @dlci: channel
+ * @mask: modem status line bits
+ *
+ * The function returns if:
+ * - any given modem status line bit changed
+ * - the wait event function got interrupted (e.g. by a signal)
+ * - the underlying DLCI was closed
+ * - the underlying ldisc device was removed
+ */
+static int gsm_wait_modem_change(struct gsm_dlci *dlci, u32 mask)
+{
+ struct gsm_mux *gsm = dlci->gsm;
+ u32 old = dlci->modem_rx;
+ int ret;
+
+ ret = wait_event_interruptible(gsm->event, gsm->dead ||
+ dlci->state != DLCI_OPEN ||
+ (old ^ dlci->modem_rx) & mask);
+ if (gsm->dead)
+ return -ENODEV;
+ if (dlci->state != DLCI_OPEN)
+ return -EL2NSYNC;
+ return ret;
+}
+
static bool gsm_carrier_raised(struct tty_port *port)
{
struct gsm_dlci *dlci = container_of(port, struct gsm_dlci, port);
@@ -4034,6 +4063,8 @@ static int gsmtty_ioctl(struct tty_struct *tty,
gsm_destroy_network(dlci);
mutex_unlock(&dlci->mutex);
return 0;
+ case TIOCMIWAIT:
+ return gsm_wait_modem_change(dlci, (u32)arg);
default:
return -ENOIOCTLCMD;
}