Re: [PATCH] Bluetooth: hci_sync: Fix BLE devices were unable to disable the wakeup function

[Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx>]

Hi Clancy,

On Thu, Jan 4, 2024 at 9:56 PM <clancy_shang@xxxxxxx> wrote:
>
> From: Clancy Shang <clancy.shang@xxxxxxxxxxx>
>
> when BLE master enter suspend,  it does not delete the peripheral that
> in acceptlist. so if disable the wakeup function, the BLE master scans with
> basic filter next time, the peripheral can be scanned which is unexpected
>
> Signed-off-by: Clancy Shang <clancy.shang@xxxxxxxxxxx>
> ---
>  net/bluetooth/hci_sync.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
> index d85a7091a116..abc7f614da5f 100644
> --- a/net/bluetooth/hci_sync.c
> +++ b/net/bluetooth/hci_sync.c
> @@ -2533,6 +2533,7 @@ static u8 hci_update_accept_list_sync(struct hci_dev *hdev)
>         struct bdaddr_list *b, *t;
>         u8 num_entries = 0;
>         bool pend_conn, pend_report;
> +       struct hci_conn_params *conn_params;
>         u8 filter_policy;
>         size_t i, n;
>         int err;
> @@ -2585,6 +2586,15 @@ static u8 hci_update_accept_list_sync(struct hci_dev *hdev)
>                         continue;
>                 }
>
> +               conn_params = hci_conn_params_lookup(hdev, &b->bdaddr, b->bdaddr_type);
> +               /* During suspend, only wakeable devices can be in acceptlist */
> +               if (conn_params && hdev->suspended &&
> +                   !(conn_params->flags & HCI_CONN_FLAG_REMOTE_WAKEUP)) {
> +                       hci_le_del_accept_list_sync(hdev, &b->bdaddr,
> +                                                   b->bdaddr_type);
> +                       continue;
> +               }

This might require a lock since that is not a copy of the conn_params
which can be updated concurrently, so perhaps something like the
following is might be safer:

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index b3141e3f9cf6..eeb73a54fd26 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -2206,8 +2206,11 @@ static int hci_le_add_accept_list_sync(struct
hci_dev *hdev,

        /* During suspend, only wakeable devices can be in acceptlist */
        if (hdev->suspended &&
-           !(params->flags & HCI_CONN_FLAG_REMOTE_WAKEUP))
+           !(params->flags & HCI_CONN_FLAG_REMOTE_WAKEUP)) {
+               hci_le_del_accept_list_sync(hdev, &params->bdaddr,
+                                           params->bdaddr_type);
                return 0;
+       }

        /* Select filter policy to accept all advertising */
        if (*num_entries >= hdev->le_accept_list_size)

>                 num_entries++;
>         }
>
> --
> 2.25.1
>


-- 
Luiz Augusto von Dentz