This patch looks like it should be in the 3.9-stable tree, should we apply
it?
------------------
From: "Daniel Drake <[email protected]>"
commit ea05fea9042620ac3b8ab9a3e5e4d2ed80c89244 upstream
There is currently a race condition in the btmrvl_remove_card() which
is causing hangs on suspend for OLPC. When the race occurs,
kthread_stop() never returns.
The problem is that btmrvl_service_main_thread() calls kthread_should_stop()
and then does a fair number of things before restarting the loop and
sleeping.
If the thread gets stopped after kthread_should_stop() is checked, but
before the sleep happens, the thread will go to sleep and won't necessarily
be woken up.
Move the kthread_should_stop() check into a race-free place.
Signed-off-by: Daniel Drake <[email protected]>
Signed-off-by: Gustavo Padovan <[email protected]>
Signed-off-by: John W. Linville <[email protected]>
Signed-off-by: Jonghwan Choi <[email protected]>
---
drivers/bluetooth/btmrvl_main.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/bluetooth/btmrvl_main.c
b/drivers/bluetooth/btmrvl_main.c
index 3a4343b..9a9f518 100644
--- a/drivers/bluetooth/btmrvl_main.c
+++ b/drivers/bluetooth/btmrvl_main.c
@@ -498,6 +498,10 @@ static int btmrvl_service_main_thread(void *data)
add_wait_queue(&thread->wait_q, &wait);
set_current_state(TASK_INTERRUPTIBLE);
+ if (kthread_should_stop()) {
+ BT_DBG("main_thread: break from main thread");
+ break;
+ }
if (adapter->wakeup_tries ||
((!adapter->int_count) &&
@@ -513,11 +517,6 @@ static int btmrvl_service_main_thread(void *data)
BT_DBG("main_thread woke up");
- if (kthread_should_stop()) {
- BT_DBG("main_thread: break from main thread");
- break;
- }
-
spin_lock_irqsave(&priv->driver_lock, flags);
if (adapter->int_count) {
adapter->int_count = 0;
--
1.7.9.5
Jonghwan Choi <[email protected]> writes:
> This patch looks like it should be in the 3.9-stable tree, should we apply
> it?
This seems to be applicable to all the other stable kernels as well
(and its a clean cherry-pick for all of them). I'm queuing it for the
3.5 kernel.
Cheers,
--
Luis
>
> ------------------
>
> From: "Daniel Drake <[email protected]>"
>
> commit ea05fea9042620ac3b8ab9a3e5e4d2ed80c89244 upstream
>
> There is currently a race condition in the btmrvl_remove_card() which
> is causing hangs on suspend for OLPC. When the race occurs,
> kthread_stop() never returns.
>
> The problem is that btmrvl_service_main_thread() calls kthread_should_stop()
> and then does a fair number of things before restarting the loop and
> sleeping.
>
> If the thread gets stopped after kthread_should_stop() is checked, but
> before the sleep happens, the thread will go to sleep and won't necessarily
> be woken up.
>
> Move the kthread_should_stop() check into a race-free place.
>
> Signed-off-by: Daniel Drake <[email protected]>
> Signed-off-by: Gustavo Padovan <[email protected]>
> Signed-off-by: John W. Linville <[email protected]>
> Signed-off-by: Jonghwan Choi <[email protected]>
> ---
> drivers/bluetooth/btmrvl_main.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/bluetooth/btmrvl_main.c
> b/drivers/bluetooth/btmrvl_main.c
> index 3a4343b..9a9f518 100644
> --- a/drivers/bluetooth/btmrvl_main.c
> +++ b/drivers/bluetooth/btmrvl_main.c
> @@ -498,6 +498,10 @@ static int btmrvl_service_main_thread(void *data)
> add_wait_queue(&thread->wait_q, &wait);
>
> set_current_state(TASK_INTERRUPTIBLE);
> + if (kthread_should_stop()) {
> + BT_DBG("main_thread: break from main thread");
> + break;
> + }
>
> if (adapter->wakeup_tries ||
> ((!adapter->int_count) &&
> @@ -513,11 +517,6 @@ static int btmrvl_service_main_thread(void *data)
>
> BT_DBG("main_thread woke up");
>
> - if (kthread_should_stop()) {
> - BT_DBG("main_thread: break from main thread");
> - break;
> - }
> -
> spin_lock_irqsave(&priv->driver_lock, flags);
> if (adapter->int_count) {
> adapter->int_count = 0;