cdc-acm: remove dead code

The wait_event_interruptible_timeout in acm_port_down is
never reached. Remove it to avoid possible deadlocks
with the big tty mutex if someone were to start using
the blocking version of acm_port_down.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 9 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 89d260d6b031..1833b3a71515 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -636,19 +636,13 @@ static void acm_tty_unregister(struct acm *acm)
 
 static int acm_tty_chars_in_buffer(struct tty_struct *tty);
 
-static void acm_port_down(struct acm *acm, int drain)
+static void acm_port_down(struct acm *acm)
 {
         int i, nr = acm->rx_buflimit;
         mutex_lock(&open_mutex);
         if (acm->dev) {
                 usb_autopm_get_interface(acm->control);
                 acm_set_control(acm, acm->ctrlout = 0);
-                /* try letting the last writes drain naturally */
-                if (drain) {
-                        wait_event_interruptible_timeout(acm->drain_wait,
-                                (ACM_NW == acm_wb_is_avail(acm)) || !acm->dev,
-                                        ACM_CLOSE_TIMEOUT * HZ);
-                }
                 usb_kill_urb(acm->ctrlurb);
                 for (i = 0; i < ACM_NW; i++)
                         usb_kill_urb(acm->wb[i].urb);
@@ -664,7 +658,7 @@ static void acm_tty_hangup(struct tty_struct *tty)
 {
         struct acm *acm = tty->driver_data;
         tty_port_hangup(&acm->port);
-        acm_port_down(acm, 0);
+        acm_port_down(acm);
 }
 
 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
@@ -685,7 +679,7 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
                 mutex_unlock(&open_mutex);
                 return;
         }
-        acm_port_down(acm, 0);
+        acm_port_down(acm);
         tty_port_close_end(&acm->port, tty);
         tty_port_tty_set(&acm->port, NULL);
 }