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 <oneukum@suse.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/uwb/neh.c b/drivers/uwb/neh.c
index a269937be1b8..8cb71bb333c2 100644
--- a/drivers/uwb/neh.c
+++ b/drivers/uwb/neh.c
@@ -107,6 +107,7 @@ struct uwb_rc_neh {
         u8 evt_type;
         __le16 evt;
         u8 context;
+        u8 completed;
         uwb_rc_cmd_cb_f cb;
         void *arg;
 
@@ -409,6 +410,7 @@ static void uwb_rc_neh_grok_event(struct uwb_rc *rc, struct uwb_rceb *rceb, size
         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);
@@ -422,7 +424,11 @@ static void uwb_rc_neh_grok_event(struct uwb_rc *rc, struct uwb_rceb *rceb, size
         } 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",
@@ -568,6 +574,10 @@ static void uwb_rc_neh_timer(unsigned long arg)
         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