[ 014/167] [PATCH] uwb: fix use of del_timer_sync() in interrupt

From: Ben Hutchings
Date: Wed May 09 2012 - 02:35:14 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Oliver Neukum <oliver@xxxxxxxxxx>

commit 9426cd05682745d1024dbabdec5631309bd2f480 upstream.

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

Signed-off-by: Oliver Neukum <oneukum@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/uwb/neh.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/uwb/neh.c b/drivers/uwb/neh.c
index a269937..8cb71bb 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
--
1.7.10



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