tty: moxa: Fix modem op locking
This is overkill and mostly not needed
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index d180aa9..ac06d01 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -139,7 +139,7 @@
int cflag;
unsigned long statusflags;
- u8 DCDState;
+ u8 DCDState; /* Protected by the port lock */
u8 lineCtrl;
u8 lowChkFlag;
};
@@ -1141,9 +1141,9 @@
struct moxa_port *ch = container_of(port, struct moxa_port, port);
int dcd;
- spin_lock_bh(&moxa_lock);
+ spin_lock_irq(&port->lock);
dcd = ch->DCDState;
- spin_unlock_bh(&moxa_lock);
+ spin_unlock_irq(&port->lock);
return dcd;
}
@@ -1267,16 +1267,9 @@
static int moxa_tiocmget(struct tty_struct *tty, struct file *file)
{
- struct moxa_port *ch;
+ struct moxa_port *ch = tty->driver_data;
int flag = 0, dtr, rts;
- mutex_lock(&moxa_openlock);
- ch = tty->driver_data;
- if (!ch) {
- mutex_unlock(&moxa_openlock);
- return -EINVAL;
- }
-
MoxaPortGetLineOut(ch, &dtr, &rts);
if (dtr)
flag |= TIOCM_DTR;
@@ -1289,7 +1282,6 @@
flag |= TIOCM_DSR;
if (dtr & 4)
flag |= TIOCM_CD;
- mutex_unlock(&moxa_openlock);
return flag;
}
@@ -1368,15 +1360,20 @@
static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
{
struct tty_struct *tty;
+ unsigned long flags;
dcd = !!dcd;
+ spin_lock_irqsave(&p->port.lock, flags);
if (dcd != p->DCDState) {
+ p->DCDState = dcd;
+ spin_unlock_irqrestore(&p->port.lock, flags);
tty = tty_port_tty_get(&p->port);
if (tty && C_CLOCAL(tty) && !dcd)
tty_hangup(tty);
tty_kref_put(tty);
}
- p->DCDState = dcd;
+ else
+ spin_unlock_irqrestore(&p->port.lock, flags);
}
static int moxa_poll_port(struct moxa_port *p, unsigned int handle,
@@ -1878,9 +1875,7 @@
val &= 0x0B;
if (val & 8)
val |= 4;
- spin_lock_bh(&moxa_lock);
moxa_new_dcdstate(port, val & 8);
- spin_unlock_bh(&moxa_lock);
val &= 7;
return val;
}