Messages in this thread Patch in this message | | | From | Luis Henriques <> | Subject | [PATCH 44/50] Bluetooth: btmrvl: fix thread stopping race | Date | Tue, 2 Jul 2013 12:07:32 +0100 |
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3.5.7.16 -stable review patch. If anyone has any objections, please let me know.
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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> Cc: Jonghwan Choi <jhbird.choi@samsung.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.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 dc304de..2c63a21 100644 --- a/drivers/bluetooth/btmrvl_main.c +++ b/drivers/bluetooth/btmrvl_main.c @@ -496,6 +496,10 @@ 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) && @@ -511,11 +515,6 @@ 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; -- 1.8.1.2
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