1 files changed, 62 insertions, 0 deletions
diff --git a/tty/cdc-acm-remove-dead-code.patch b/tty/cdc-acm-remove-dead-code.patch
new file mode 100644
index 00000000000000..6b587a7f169571
--- /dev/null
+++ b/tty/cdc-acm-remove-dead-code.patch
@@ -0,0 +1,62 @@
+From arnd@arndb.de  Wed Jun 16 13:42:49 2010
+From: Arnd Bergmann <arnd@arndb.de>
+Date: Tue,  1 Jun 2010 22:53:04 +0200
+Subject: cdc-acm: remove dead code
+To: Greg KH <gregkh@suse.de>
+Cc: linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>, Alan Cox <alan@lxorguk.ukuu.org.uk>, Frederic Weisbecker <fweisbec@gmail.com>, John Kacur <jkacur@redhat.com>
+Message-ID: <1275425591-8803-25-git-send-email-arnd@arndb.de>
+
+
+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>
+
+---
+ drivers/usb/class/cdc-acm.c |   12 +++---------
+ 1 file changed, 3 insertions(+), 9 deletions(-)
+
+--- a/drivers/usb/class/cdc-acm.c
++++ b/drivers/usb/class/cdc-acm.c
+@@ -636,19 +636,13 @@ static void acm_tty_unregister(struct ac
+ 
+ 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_st
+ {
+ 	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_str
+ 		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);
+ }