USB: cdc-acm: remove unused drain-delay code

The drain-delay code is no longer used, so remove it.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/class/cdc-acm.c

@@ -50,9 +50,6 @@
 #include "cdc-acm.h"
 
 
-#define ACM_CLOSE_TIMEOUT	15	/* seconds to let writes drain */
-
-
 #define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek"
 #define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
 
@@ -507,8 +504,6 @@ static void acm_write_bulk(struct urb *urb)
 	spin_unlock_irqrestore(&acm->write_lock, flags);
 	if (ACM_READY(acm))
 		schedule_work(&acm->work);
-	else
-		wake_up_interruptible(&acm->drain_wait);
 }
 
 static void acm_softint(struct work_struct *work)
@@ -1155,7 +1150,6 @@ static int acm_probe(struct usb_interface *intf,
 	acm->urb_task.func = acm_rx_tasklet;
 	acm->urb_task.data = (unsigned long) acm;
 	INIT_WORK(&acm->work, acm_softint);
-	init_waitqueue_head(&acm->drain_wait);
 	spin_lock_init(&acm->throttle_lock);
 	spin_lock_init(&acm->write_lock);
 	spin_lock_init(&acm->read_lock);

drivers/usb/class/cdc-acm.h

@@ -112,7 +112,6 @@ struct acm {
 	struct mutex mutex;
 	struct usb_cdc_line_coding line;		/* bits, stop, parity */
 	struct work_struct work;			/* work queue entry for line discipline waking up */
-	wait_queue_head_t drain_wait;			/* close processing */
 	struct tasklet_struct urb_task;                 /* rx processing */
 	spinlock_t throttle_lock;			/* synchronize throtteling and read callback */
 	unsigned int ctrlin;				/* input control lines (DCD, DSR, RI, break, overruns) */