Re: [PATCH 2/2] Bluetooth: Remove wait for delayed work to finish
From: Andre Guedes <hidden>
Date: 2012-01-18 19:34:23
Hi Ulisses, On Wed, Jan 18, 2012 at 9:48 AM, Ulisses Furquim [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Do not wait for delayed work to finish where it's not needed. In the case of adv_work the handler is already protected by the hdev lock and removing the wait we also avoid introducing deadlocks involving the delayed work lock. Signed-off-by: Ulisses Furquim <redacted> --- net/bluetooth/hci_core.c | 2 +- net/bluetooth/hci_event.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index a7b7200..b4041be 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c@@ -1731,7 +1731,7 @@ void hci_unregister_dev(struct hci_dev *hdev)hci_del_sysfs(hdev); - cancel_delayed_work_sync(&hdev->adv_work); + cancel_delayed_work(&hdev->adv_work);
I'm afraid we'll introduce a race condition if we don't use the _sync variant at hci_unregister_dev. If we don't wait adv_work finish it may be running after hdev object is freed.
quoted hunk ↗ jump to hunk
destroy_workqueue(hdev->workqueue);diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index c2fe964..f28cbae 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c@@ -1045,7 +1045,7 @@ static void hci_cc_le_set_scan_enable(struct hci_dev *hdev,case LE_SCANNING_ENABLED: set_bit(HCI_LE_SCAN, &hdev->dev_flags); - cancel_delayed_work_sync(&hdev->adv_work); + cancel_delayed_work(&hdev->adv_work); hci_dev_lock(hdev); hci_adv_entries_clear(hdev);
BR, Andre