s390/3270: fix view reference counting

The tty3270_close function set tty->driver_data to NULL after the
open count dropped to zero but tty3270_cleanup still needs the
pointer to the tty3270 view to drop the reference count.

Move the clearing of tty->driver_data to tty3270_cleanup and
drop the unnecessary tty_port_tty_set calls in tty3270_install.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
index 345f392b50b2..e8afa07f082e 100644
--- a/drivers/s390/char/tty3270.c
+++ b/drivers/s390/char/tty3270.c
@@ -924,10 +924,8 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
                 tty->winsize.ws_row = tp->view.rows - 2;
                 tty->winsize.ws_col = tp->view.cols;
                 tp->port.low_latency = 0;
-                /* why to reassign? */
-                tty_port_tty_set(&tp->port, tty);
                 tp->inattr = TF_INPUT;
-                return tty_port_install(&tp->port, driver, tty);
+                goto port_install;
         }
         if (tty3270_max_index < tty->index + 1)
                 tty3270_max_index = tty->index + 1;
@@ -953,7 +951,6 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
                 return rc;
         }
 
-        tty_port_tty_set(&tp->port, tty);
         tp->port.low_latency = 0;
         tty->winsize.ws_row = tp->view.rows - 2;
         tty->winsize.ws_col = tp->view.cols;
@@ -975,6 +972,7 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
 
         raw3270_activate_view(&tp->view);
 
+port_install:
         rc = tty_port_install(&tp->port, driver, tty);
         if (rc) {
                 raw3270_put_view(&tp->view);
@@ -1011,18 +1009,18 @@ tty3270_close(struct tty_struct *tty, struct file * filp)
 
         if (tty->count > 1)
                 return;
-        if (tp) {
-                tty->driver_data = NULL;
+        if (tp)
                 tty_port_tty_set(&tp->port, NULL);
-        }
 }
 
 static void tty3270_cleanup(struct tty_struct *tty)
 {
         struct tty3270 *tp = tty->driver_data;
 
-        if (tp)
+        if (tp) {
+                tty->driver_data = NULL;
                 raw3270_put_view(&tp->view);
+        }
 }
 
 /*