Hi Jakub,
> On Thu, Nov 20, 2014 at 2:24 PM, Jakub Pawlowski <jpawlowski@xxxxxxxxxx> wrote:
> On Thu, Nov 20, 2014 at 1:48 PM, Arman Uguray <armansito@xxxxxxxxxxxx> wrote:
>> Hi Jakub,
>>
>>> On Thu, Nov 20, 2014 at 9:51 AM, Jakub Pawlowski <jpawlowski@xxxxxxxxxx> 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 <jpawlowski@xxxxxxxxxx>
>>> ---
>>> 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
>>>
>>> --
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>>
>> Thanks,
>> Arman
Arman
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