uwb: fix use of del_timer_sync() in interrupt

del_timer_sync() cannot be used in interrupt.
Replace it with del_timer() and a flag

Signed-off-by: Oliver Neukum <[e-mail]>
Cc: stable <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/uwb/neh.c

···
 	u8 evt_type;
 	__le16 evt;
 	u8 context;
+	u8 completed;
 	uwb_rc_cmd_cb_f cb;
 	void *arg;
 
···
 	struct device *dev = &rc->uwb_dev.dev;
 	struct uwb_rc_neh *neh;
 	struct uwb_rceb *notif;
+	unsigned long flags;
 
 	if (rceb->bEventContext == 0) {
 		notif = kmalloc(size, GFP_ATOMIC);
···
 	} else {
 		neh = uwb_rc_neh_lookup(rc, rceb);
 		if (neh) {
-			del_timer_sync(&neh->timer);
+			spin_lock_irqsave(&rc->neh_lock, flags);
+			/* to guard against a timeout */
+			neh->completed = 1;
+			del_timer(&neh->timer);
+			spin_unlock_irqrestore(&rc->neh_lock, flags);
 			uwb_rc_neh_cb(neh, rceb, size);
 		} else
 			dev_warn(dev, "event 0x%02x/%04x/%02x (%zu bytes): nobody cared\n",
···
 	unsigned long flags;
 
 	spin_lock_irqsave(&rc->neh_lock, flags);
+	if (neh->completed) {
+		spin_unlock_irqrestore(&rc->neh_lock, flags);
+		return;
+	}
 	if (neh->context)
 		__uwb_rc_neh_rm(rc, neh);
 	else