Hi Maintainers,
Could you take a look at this patch?
Thanks,
Archie
On Wed, 3 Nov 2021 at 13:33, Archie Pusaka <apusaka@xxxxxxxxxx> wrote:
>
> From: Archie Pusaka <apusaka@xxxxxxxxxxxx>
>
> This event is received when the controller stops advertising,
> specifically for these three reasons:
> (a) Connection is successfully created (success).
> (b) Timeout is reached (error).
> (c) Number of advertising events is reached (error).
> (*) This event is NOT generated when the host stops the advertisement.
> Refer to the BT spec ver 5.3 vol 4 part E sec 7.7.65.18. Note that the
> section was revised from BT spec ver 5.0 vol 2 part E sec 7.7.65.18
> which was ambiguous about (*).
>
> Some chips (e.g. RTL8822CE) send this event when the host stops the
> advertisement with status = HCI_ERROR_CANCELLED_BY_HOST (due to (*)
> above). This is treated as an error and the advertisement will be
> removed and userspace will be informed via MGMT event.
>
> On suspend, we are supposed to temporarily disable advertisements,
> and continue advertising on resume. However, due to the behavior
> above, the advertisements are removed instead.
>
> This patch returns early if HCI_ERROR_CANCELLED_BY_HOST is received.
>
> Btmon snippet of the unexpected behavior:
> @ MGMT Command: Remove Advertising (0x003f) plen 1
> Instance: 1
> < HCI Command: LE Set Extended Advertising Enable (0x08|0x0039) plen 6
> Extended advertising: Disabled (0x00)
> Number of sets: 1 (0x01)
> Entry 0
> Handle: 0x01
> Duration: 0 ms (0x00)
> Max ext adv events: 0
> > HCI Event: LE Meta Event (0x3e) plen 6
> LE Advertising Set Terminated (0x12)
> Status: Operation Cancelled by Host (0x44)
> Handle: 1
> Connection handle: 0
> Number of completed extended advertising events: 5
> > HCI Event: Command Complete (0x0e) plen 4
> LE Set Extended Advertising Enable (0x08|0x0039) ncmd 2
> Status: Success (0x00)
>
> Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx>
>
> ---
>
> Changes in v2:
> * Split clearing HCI_LE_ADV into its own patch
> * Reword comments
>
> include/net/bluetooth/hci.h | 1 +
> net/bluetooth/hci_event.c | 12 ++++++++++++
> 2 files changed, 13 insertions(+)
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index 63065bc01b76..84db6b275231 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -566,6 +566,7 @@ enum {
> #define HCI_ERROR_INVALID_LL_PARAMS 0x1e
> #define HCI_ERROR_UNSPECIFIED 0x1f
> #define HCI_ERROR_ADVERTISING_TIMEOUT 0x3c
> +#define HCI_ERROR_CANCELLED_BY_HOST 0x44
>
> /* Flow control modes */
> #define HCI_FLOW_CTL_MODE_PACKET_BASED 0x00
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index d4b75a6cfeee..7d875927c48b 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -5538,6 +5538,18 @@ static void hci_le_ext_adv_term_evt(struct hci_dev *hdev, struct sk_buff *skb)
>
> adv = hci_find_adv_instance(hdev, ev->handle);
>
> + /* The Bluetooth Core 5.3 specification clearly states that this event
> + * shall not be sent when the Host disables the advertising set. So in
> + * case of HCI_ERROR_CANCELLED_BY_HOST, just ignore the event.
> + *
> + * When the Host disables an advertising set, all cleanup is done via
> + * its command callback and not needed to be duplicated here.
> + */
> + if (ev->status == HCI_ERROR_CANCELLED_BY_HOST) {
> + bt_dev_warn_ratelimited(hdev, "Unexpected advertising set terminated event");
> + return;
> + }
> +
> if (ev->status) {
> if (!adv)
> return;
> --
> 2.33.1.1089.g2158813163f-goog
>
