Messages in this thread Patch in this message | | | From | Jonghwan Choi <> | Subject | [PATCH 3.9-stable] Bluetooth: btmrvl: fix thread stopping race | Date | Fri, 28 Jun 2013 08:47:02 +0900 |
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This patch looks like it should be in the 3.9-stable tree, should we apply it?
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From: "Daniel Drake <dsd@laptop.org>"
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 <dsd@laptop.org> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> --- 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
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