Hi Jakub,
> When using LE_SCAN_FILTER_DUP_ENABLE, some controllers would send
> advertising report from each LE device only once. That means that we
> don't get any updates on RSSI value, and makes Service Discovery very
> slow. This patch adds restarting scan when in Service Discovery, and
> device with filtered uuid is found, but it's not in RSSI range to send
> event yet. This way if device moves into range, we will quickly get RSSI
> update.
>
> Signed-off-by: Jakub Pawlowski <jpawlowski@xxxxxxxxxx>
> ---
> include/net/bluetooth/hci_core.h | 1 +
> net/bluetooth/mgmt.c | 46 +++++++++++++++++++++++++++++++++++++---
> 2 files changed, 44 insertions(+), 3 deletions(-)
>
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index de019eb..aa5bea0 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -1328,6 +1328,7 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event);
> #define DISCOV_INTERLEAVED_TIMEOUT 5120 /* msec */
> #define DISCOV_INTERLEAVED_INQUIRY_LEN 0x04
> #define DISCOV_BREDR_INQUIRY_LEN 0x08
> +#define DISCOV_LE_RESTART_DELAY msecs_to_jiffies(200) /* msec */
>
> int mgmt_control(struct sock *sk, struct msghdr *msg, size_t len);
> int mgmt_new_settings(struct hci_dev *hdev);
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index c2b5f8a..67ef0ea 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -7195,6 +7195,20 @@ static bool eir_has_uuids(u8 *eir, u16 eir_len, u16 uuid_count, u8 (*uuids)[16])
> return false;
> }
>
> +static void restart_le_scan(struct hci_dev *hdev)
> +{
> + /* If controller is not scanning we are done. */
> + if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
> + return;
> +
> + if (time_after(jiffies + DISCOV_LE_RESTART_DELAY,
> + hdev->discovery.scan_end))
> + return;
> +
> + queue_delayed_work(hdev->workqueue, &hdev->le_scan_restart,
> + DISCOV_LE_RESTART_DELAY);
> +}
> +
> void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
> u8 addr_type, u8 *dev_class, s8 rssi, u32 flags,
> u8 *eir, u16 eir_len, u8 *scan_rsp, u8 scan_rsp_len)
> @@ -7224,7 +7238,9 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
> * the results are also dropped.
> */
> if (hdev->discovery.rssi != HCI_RSSI_INVALID &&
> - (rssi < hdev->discovery.rssi || rssi == HCI_RSSI_INVALID))
> + (rssi == HCI_RSSI_INVALID ||
> + (rssi < hdev->discovery.rssi &&
> + !test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks))))
> return;
there is a comment above this if clause. So that one needs to be adjusted to take this new case into account.
> /* Make sure that the buffer is big enough. The 5 extra bytes
> @@ -7258,12 +7274,20 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
> * kept and checking possible scan response data
> * will be skipped.
> */
> - if (hdev->discovery.uuid_count > 0)
> + if (hdev->discovery.uuid_count > 0) {
> match = eir_has_uuids(eir, eir_len,
> hdev->discovery.uuid_count,
> hdev->discovery.uuids);
> - else
> + /* we have service match. If duplicate filtering doesn't
> + * honour RSSI hanges, restart scan to make sure we'll
> + * get RSSI updates
> + */
Lets fix the spelling here first. Also skip the "we have service match". That is just something out of context and hard to read.
/* If duplicate filtering does not report RSSI changes, then
* restart scanning to ensure updated result with updated
* RSSI values.
*/
> + if (match && test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER,
> + &hdev->quirks))
> + restart_le_scan(hdev);
> + } else {
> match = true;
> + }
>
> if (!match && !scan_rsp_len)
> return;
> @@ -7296,6 +7320,14 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
> hdev->discovery.uuid_count,
> hdev->discovery.uuids))
> return;
> +
> + /* we have service match. If duplicate filtering doesn't
> + * honour RSSI hanges, restart scan to make sure we'll
> + * get RSSI updates
> + */
Same here.
> + if (test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER,
> + &hdev->quirks))
This really do not fit into a single line?
> + restart_le_scan(hdev);
> }
>
> /* Append scan response data to event */
> @@ -7309,6 +7341,14 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
> return;
> }
>
> + /* Check again wether RSSI value doesn't meet Service Discovery
> + * threshold. This might evaluate to true only if
> + * HCI_QUIRK_STRICT_DUPLICATE_FILTER is set.
> + */
/* Validate the reported RSSI value against the RSSI threshold once more in
* case HCI_QUIRK_STRICT_DUPLICATE_FILTER forced a restart of LE scanning.
*/
> + if (hdev->discovery.rssi != HCI_RSSI_INVALID &&
> + rssi < hdev->discovery.rssi)
> + return;
> +
> ev->eir_len = cpu_to_le16(eir_len + scan_rsp_len);
> ev_size = sizeof(*ev) + eir_len + scan_rsp_len;
Regards
Marcel
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