2020-03-17 05:41:59

by Manish Mandlik

Subject: [PATCH] Bluetooth: Do not cancel advertising when starting a scan

From: Dmitry Grinberg <[email protected]>

BlueZ cancels adv when starting a scan, but does not cancel a scan when
starting to adv. Neither is required, so this brings both to a
consistent state (of not affecting each other). Some very rare (I've
never seen one) BT 4.0 chips will fail to do both at once. Even this is
ok since the command that will fail will be the second one, and thus the
common sense logic of first-come-first-served is preserved for BLE
requests.

Signed-off-by: Dmitry Grinberg <[email protected]>
Signed-off-by: Manish Mandlik <[email protected]>
---

net/bluetooth/hci_request.c | 17 -----------------
1 file changed, 17 deletions(-)

diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index bf83179ab9d19..649e1e5ed446a 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -2727,23 +2727,6 @@ static int active_scan(struct hci_request *req, unsigned long opt)

BT_DBG("%s", hdev->name);

- if (hci_dev_test_flag(hdev, HCI_LE_ADV)) {
- hci_dev_lock(hdev);
-
- /* Don't let discovery abort an outgoing connection attempt
- * that's using directed advertising.
- */
- if (hci_lookup_le_connect(hdev)) {
- hci_dev_unlock(hdev);
- return -EBUSY;
- }
-
- cancel_adv_timeout(hdev);
- hci_dev_unlock(hdev);
-
- __hci_req_disable_advertising(req);
- }
-
/* If controller is scanning, it means the background scanning is
* running. Thus, we should temporarily stop it in order to set the
* discovery scanning parameters.
--
2.25.1.481.gfbce0eb801-goog

2020-03-18 11:26:45

by Marcel Holtmann

Subject: Re: [PATCH] Bluetooth: Do not cancel advertising when starting a scan

Hi Manish,

> BlueZ cancels adv when starting a scan, but does not cancel a scan when
> starting to adv. Neither is required, so this brings both to a
> consistent state (of not affecting each other). Some very rare (I've
> never seen one) BT 4.0 chips will fail to do both at once. Even this is
> ok since the command that will fail will be the second one, and thus the
> common sense logic of first-come-first-served is preserved for BLE
> requests.
>
> Signed-off-by: Dmitry Grinberg <[email protected]>
> Signed-off-by: Manish Mandlik <[email protected]>
> ---
>
> net/bluetooth/hci_request.c | 17 -----------------
> 1 file changed, 17 deletions(-)

patch has been applied to bluetooth-next tree.

If you know the controller that doesn’t support this, can we blacklist that one and just disable advertising (peripheral mode) for that controller.

Regards

Marcel