tty: refcount the epca driver

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 12 deletions

diff --git a/drivers/char/epca.c b/drivers/char/epca.c
index e07d7925c300..7a697055e4f6 100644
--- a/drivers/char/epca.c
+++ b/drivers/char/epca.c
@@ -175,7 +175,7 @@ static unsigned termios2digi_h(struct channel *ch, unsigned);
 static unsigned termios2digi_i(struct channel *ch, unsigned);
 static unsigned termios2digi_c(struct channel *ch, unsigned);
 static void epcaparam(struct tty_struct *, struct channel *);
-static void receive_data(struct channel *);
+static void receive_data(struct channel *, struct tty_struct *tty);
 static int pc_ioctl(struct tty_struct *, struct file *,
                         unsigned int, unsigned long);
 static int info_ioctl(struct tty_struct *, struct file *,
@@ -473,7 +473,7 @@ static void pc_close(struct tty_struct *tty, struct file *filp)
         spin_lock_irqsave(&port->lock, flags);
         tty->closing = 0;
         ch->event = 0;
-        port->tty = NULL;
+        tty_port_tty_set(port, NULL);
         spin_unlock_irqrestore(&port->lock, flags);
 
         if (port->blocked_open) {
@@ -1029,8 +1029,11 @@ static void __exit epca_module_exit(void)
                 }
                 ch = card_ptr[crd];
                 for (count = 0; count < bd->numports; count++, ch++) {
-                        if (ch && ch->port.tty)
-                                tty_hangup(ch->port.tty);
+                        struct tty_struct *tty = tty_port_tty_get(&ch->port);
+                        if (tty) {
+                                tty_hangup(tty);
+                                tty_kref_put(tty);
+                        }
                 }
         }
         pci_unregister_driver(&epca_driver);
@@ -1441,7 +1444,7 @@ static void post_fep_init(unsigned int crd)
                 ch->boardnum   = crd;
                 ch->channelnum = i;
                 ch->magic      = EPCA_MAGIC;
-                ch->port.tty        = NULL;
+                tty_port_tty_set(&ch->port, NULL);
 
                 if (shrinkmem) {
                         fepcmd(ch, SETBUFFER, 32, 0, 0, 0);
@@ -1635,8 +1638,9 @@ static void doevent(int crd)
                 if (bc == NULL)
                         goto next;
 
+                tty = tty_port_tty_get(&ch->port);
                 if (event & DATA_IND)  { /* Begin DATA_IND */
-                        receive_data(ch);
+                        receive_data(ch, tty);
                         assertgwinon(ch);
                 } /* End DATA_IND */
                 /* else *//* Fix for DCD transition missed bug */
@@ -1651,7 +1655,6 @@ static void doevent(int crd)
                                         pc_sched_event(ch, EPCA_EVENT_HANGUP);
                         }
                 }
-                tty = ch->port.tty;
                 if (tty) {
                         if (event & BREAK_IND) {
                                 /* A break has been indicated */
@@ -1671,6 +1674,7 @@ static void doevent(int crd)
                                         tty_wakeup(tty);
                                 }
                         }
+                        tty_kref_put(tty);
                 }
 next:
                 globalwinon(ch);
@@ -1965,11 +1969,10 @@ static void epcaparam(struct tty_struct *tty, struct channel *ch)
 }
 
 /* Caller holds lock */
-static void receive_data(struct channel *ch)
+static void receive_data(struct channel *ch, struct tty_struct *tty)
 {
         unchar *rptr;
         struct ktermios *ts = NULL;
-        struct tty_struct *tty;
         struct board_chan __iomem *bc;
         int dataToRead, wrapgap, bytesAvailable;
         unsigned int tail, head;
@@ -1982,7 +1985,6 @@ static void receive_data(struct channel *ch)
         globalwinon(ch);
         if (ch->statusflags & RXSTOPPED)
                 return;
-        tty = ch->port.tty;
         if (tty)
                 ts = tty->termios;
         bc = ch->brdchan;
@@ -2042,7 +2044,7 @@ static void receive_data(struct channel *ch)
         globalwinon(ch);
         writew(tail, &bc->rout);
         /* Must be called with global data */
-        tty_schedule_flip(ch->port.tty);
+        tty_schedule_flip(tty);
 }
 
 static int info_ioctl(struct tty_struct *tty, struct file *file,
@@ -2365,7 +2367,7 @@ static void do_softint(struct work_struct *work)
         struct channel *ch = container_of(work, struct channel, tqueue);
         /* Called in response to a modem change event */
         if (ch && ch->magic == EPCA_MAGIC) {
-                struct tty_struct *tty = ch->port.tty;
+                struct tty_struct *tty = tty_port_tty_get(&ch->port);;
 
                 if (tty && tty->driver_data) {
                         if (test_and_clear_bit(EPCA_EVENT_HANGUP, &ch->event)) {
@@ -2374,6 +2376,7 @@ static void do_softint(struct work_struct *work)
                                 ch->port.flags &= ~ASYNC_NORMAL_ACTIVE;
                         }
                 }
+                tty_kref_put(tty);
         }
 }