Return-Path: MIME-Version: 1.0 In-Reply-To: References: <1416505902-29931-1-git-send-email-jpawlowski@google.com> Date: Thu, 20 Nov 2014 15:37:48 -0800 Message-ID: Subject: Re: [PATCH v7 1/3] Bluetooth: add hci_restart_le_scan From: Arman Uguray To: Jakub Pawlowski Cc: BlueZ development Content-Type: text/plain; charset=UTF-8 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Jakub, > On Thu, Nov 20, 2014 at 2:24 PM, Jakub Pawlowski wrote: > On Thu, Nov 20, 2014 at 1:48 PM, Arman Uguray wrote: >> Hi Jakub, >> >>> On Thu, Nov 20, 2014 at 9:51 AM, Jakub Pawlowski wrote: >>> Currently there is no way to restart le scan. It's needed in >>> preparation for new service scan method. The way it work: it disable, >>> and then enable le scan on controller. During this restart special flag >>> is set to make sure we won't remove disable scan work from workqueue. >>> >>> Signed-off-by: Jakub Pawlowski >>> --- >>> include/net/bluetooth/hci.h | 1 + >>> include/net/bluetooth/hci_core.h | 2 ++ >>> net/bluetooth/hci_core.c | 42 ++++++++++++++++++++++++++++++++++++++++ >>> net/bluetooth/hci_event.c | 9 ++++++--- >>> 4 files changed, 51 insertions(+), 3 deletions(-) >>> >>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h >>> index e56f909..2f0bce2 100644 >>> --- a/include/net/bluetooth/hci.h >>> +++ b/include/net/bluetooth/hci.h >>> @@ -203,6 +203,7 @@ enum { >>> HCI_FAST_CONNECTABLE, >>> HCI_BREDR_ENABLED, >>> HCI_LE_SCAN_INTERRUPTED, >>> + HCI_LE_SCAN_RESTARTING, >>> }; >>> >>> /* A mask for the flags that are supposed to remain when a reset happens >>> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h >>> index 396c098..36211f9 100644 >>> --- a/include/net/bluetooth/hci_core.h >>> +++ b/include/net/bluetooth/hci_core.h >>> @@ -337,6 +337,7 @@ struct hci_dev { >>> unsigned long dev_flags; >>> >>> struct delayed_work le_scan_disable; >>> + struct delayed_work le_scan_restart; >>> >>> __s8 adv_tx_power; >>> __u8 adv_data[HCI_MAX_AD_LENGTH]; >>> @@ -1403,6 +1404,7 @@ int hci_update_random_address(struct hci_request *req, bool require_privacy, >>> u8 *own_addr_type); >>> void hci_copy_identity_address(struct hci_dev *hdev, bdaddr_t *bdaddr, >>> u8 *bdaddr_type); >>> +void hci_restart_le_scan(struct hci_dev *hdev, unsigned long delay); >>> >>> #define SCO_AIRMODE_MASK 0x0003 >>> #define SCO_AIRMODE_CVSD 0x0000 >>> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c >>> index 5c319a4..858cf54 100644 >>> --- a/net/bluetooth/hci_core.c >>> +++ b/net/bluetooth/hci_core.c >>> @@ -2557,6 +2557,7 @@ static int hci_dev_do_close(struct hci_dev *hdev) >>> cancel_delayed_work(&hdev->service_cache); >>> >>> cancel_delayed_work_sync(&hdev->le_scan_disable); >>> + cancel_delayed_work_sync(&hdev->le_scan_restart); >>> >>> if (test_bit(HCI_MGMT, &hdev->dev_flags)) >>> cancel_delayed_work_sync(&hdev->rpa_expired); >>> @@ -3851,6 +3852,8 @@ static void le_scan_disable_work(struct work_struct *work) >>> >>> BT_DBG("%s", hdev->name); >>> >>> + cancel_delayed_work_sync(&hdev->le_scan_restart); >>> + >>> hci_req_init(&req, hdev); >>> >>> hci_req_add_le_scan_disable(&req); >>> @@ -3860,6 +3863,44 @@ static void le_scan_disable_work(struct work_struct *work) >>> BT_ERR("Disable LE scanning request failed: err %d", err); >>> } >>> >>> +void hci_restart_le_scan(struct hci_dev *hdev, unsigned long delay) >>> +{ >>> + queue_delayed_work(hdev->workqueue, &hdev->le_scan_restart, delay); >>> +} >> >> Since you're exposing this as a public API, does it make sense to >> check here if a delayed work has already been scheduled? I.e. is it OK >> if this function gets called several times in succession with >> different delay values? > > Next patch introduces DISCOV_LE_RESTART_DELAY msecs_to_jiffies(300) > which is the only delay value used to schedule le_scan_restart right now. > I might change the implementation to: > > void hci_restart_le_scan(struct hci_dev *hdev) > { > queue_delayed_work(hdev->workqueue, &hdev->le_scan_restart, > DISCOV_LE_RESTART_DELAY); > } > Sure but even with a consistent delay value, is it OK to repeatedly call this function from other layers? Since this is publicly exposed from hci_core.h, any code within the subsystem can make calls to this. So you should make sure that it doesn't break this, or cover that edge case inside this function, if necessary. >> >>> + >>> +static void le_scan_restart_work_complete(struct hci_dev *hdev, u8 status) >>> +{ >>> + clear_bit(HCI_LE_SCAN_RESTARTING, &hdev->dev_flags); >>> + >>> + if (status) >>> + BT_ERR("Failed to restart LE scanning: status %d", status); >>> +} >>> + >>> +static void le_scan_restart_work(struct work_struct *work) >>> +{ >>> + struct hci_dev *hdev = container_of(work, struct hci_dev, >>> + le_scan_restart.work); >>> + struct hci_request req; >>> + struct hci_cp_le_set_scan_enable cp; >>> + int err; >>> + >>> + BT_DBG("%s", hdev->name); >>> + >>> + hci_req_init(&req, hdev); >>> + >>> + hci_req_add_le_scan_disable(&req); >>> + >>> + memset(&cp, 0, sizeof(cp)); >>> + cp.enable = LE_SCAN_ENABLE; >>> + hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp); >>> + >>> + set_bit(HCI_LE_SCAN_RESTARTING, &hdev->dev_flags); >>> + >>> + err = hci_req_run(&req, le_scan_restart_work_complete); >>> + if (err) >>> + BT_ERR("Disable LE scanning request failed: err %d", err); >>> +} >>> + >>> static void set_random_addr(struct hci_request *req, bdaddr_t *rpa) >>> { >>> struct hci_dev *hdev = req->hdev; >>> @@ -4037,6 +4078,7 @@ struct hci_dev *hci_alloc_dev(void) >>> INIT_DELAYED_WORK(&hdev->power_off, hci_power_off); >>> INIT_DELAYED_WORK(&hdev->discov_off, hci_discov_off); >>> INIT_DELAYED_WORK(&hdev->le_scan_disable, le_scan_disable_work); >>> + INIT_DELAYED_WORK(&hdev->le_scan_restart, le_scan_restart_work); >>> >>> skb_queue_head_init(&hdev->rx_q); >>> skb_queue_head_init(&hdev->cmd_q); >>> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c >>> index bd0a801..ed4d5e1 100644 >>> --- a/net/bluetooth/hci_event.c >>> +++ b/net/bluetooth/hci_event.c >>> @@ -1157,10 +1157,13 @@ static void hci_cc_le_set_scan_enable(struct hci_dev *hdev, >>> d->last_adv_data_len, NULL, 0); >>> } >>> >>> - /* Cancel this timer so that we don't try to disable scanning >>> - * when it's already disabled. >>> + /* If HCI_LE_SCAN_RESTARTING is set, don't cancel this timer, >>> + * because we're just restarting scan. Otherwise cancel it so >>> + * that we don't try to disable scanning when it's already >>> + * disabled. >>> */ >>> - cancel_delayed_work(&hdev->le_scan_disable); >>> + if (!test_bit(HCI_LE_SCAN_RESTARTING, &hdev->dev_flags)) >>> + cancel_delayed_work(&hdev->le_scan_disable); >>> >>> clear_bit(HCI_LE_SCAN, &hdev->dev_flags); >>> >>> -- >>> 2.1.0.rc2.206.gedb03e5 >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> Thanks, >> Arman Arman