From ea05fea9042620ac3b8ab9a3e5e4d2ed80c89244 Mon Sep 17 00:00:00 2001 From: Daniel Drake Date: Tue, 11 Jun 2013 15:40:20 -0400 Subject: [PATCH] Bluetooth: btmrvl: fix thread stopping race 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 Signed-off-by: Gustavo Padovan Signed-off-by: John W. Linville --- 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 3a4343b3bd6d..9a9f51875df5 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; -- 2.20.1