Hi Archie,
On Wed, Aug 10, 2022 at 1:47 AM Archie Pusaka <apusaka@xxxxxxxxxx> wrote:
>
> From: Archie Pusaka <apusaka@xxxxxxxxxxxx>
>
> Currently, we don't update the name resolving cache when receiving
> a name resolve event if the discovery phase is not in the resolving
> stage.
>
> However, if the user connect to a device while we are still resolving
> remote name for another device, discovery will be stopped, and because
> we are no longer in the discovery resolving phase, the corresponding
> remote name event will be ignored, and thus the device being resolved
> will stuck in NAME_PENDING state.
>
> If discovery is then restarted and then stopped, this will cause us to
> try cancelling the name resolve of the same device again, which is
> incorrect and might upset the controller.
Please add the Fixes tag.
> Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx>
> Reviewed-by: Ying Hsu <yinghsu@xxxxxxxxxxxx>
>
> ---
> The following steps are performed:
> (1) Prepare 2 classic peer devices that needs RNR. Put device A
> closer to DUT and device B (much) farther from DUT.
> (2) Remove all cache and previous connection from DUT
> (3) Put both peers into pairing mode, then start scanning on DUT
> (4) After ~8 sec, turn off peer B.
> *This is done so DUT can discover peer B (discovery time is 10s),
> but it hasn't started RNR. Peer is turned off to buy us the max
> time in the RNR phase (5s).
> (5) Immediately as device A is shown on UI, click to connect.
> *We thus know that the DUT is in the RNR phase and trying to
> resolve the name of peer B when we initiate connection to peer A.
> (6) Forget peer A.
> (7) Restart scan and stop scan.
> *Before the CL, stop scan is broken because we will try to cancel
> a nonexistent RNR
> (8) Restart scan again. Observe DUT can scan normally.
>
>
> net/bluetooth/hci_event.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 395c6479456f..95e145e278c9 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -2453,6 +2453,16 @@ static void hci_check_pending_name(struct hci_dev *hdev, struct hci_conn *conn,
> !test_and_set_bit(HCI_CONN_MGMT_CONNECTED, &conn->flags))
> mgmt_device_connected(hdev, conn, name, name_len);
>
> + e = hci_inquiry_cache_lookup_resolve(hdev, bdaddr, NAME_PENDING);
> +
> + if (e) {
> + list_del(&e->list);
> +
> + e->name_state = name ? NAME_KNOWN : NAME_NOT_KNOWN;
> + mgmt_remote_name(hdev, bdaddr, ACL_LINK, 0x00, e->data.rssi,
> + name, name_len);
> + }
> +
> if (discov->state == DISCOVERY_STOPPED)
> return;
>
> @@ -2462,7 +2472,6 @@ static void hci_check_pending_name(struct hci_dev *hdev, struct hci_conn *conn,
> if (discov->state != DISCOVERY_RESOLVING)
> return;
>
> - e = hci_inquiry_cache_lookup_resolve(hdev, bdaddr, NAME_PENDING);
> /* If the device was not found in a list of found devices names of which
> * are pending. there is no need to continue resolving a next name as it
> * will be done upon receiving another Remote Name Request Complete
> @@ -2470,12 +2479,6 @@ static void hci_check_pending_name(struct hci_dev *hdev, struct hci_conn *conn,
> if (!e)
> return;
>
> - list_del(&e->list);
> -
> - e->name_state = name ? NAME_KNOWN : NAME_NOT_KNOWN;
> - mgmt_remote_name(hdev, bdaddr, ACL_LINK, 0x00, e->data.rssi,
> - name, name_len);
> -
> if (hci_resolve_next_name(hdev))
> return;
>
> --
> 2.37.1.595.g718a3a8f04-goog
>
--
Luiz Augusto von Dentz
