Re: [PATCH v3 1/2] Bluetooth: Ignore HCI_ERROR_CANCELLED_BY_HOST on adv set terminated event
From: Marcel Holtmann
Date: Tue Nov 16 2021 - 09:18:36 EST
> 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 126.96.36.199. Note that the
> section was revised from BT spec ver 5.0 vol 2 part E sec 188.8.131.52
> 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>
> (no changes since v2)
> 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(+)
patch has been applied to bluetooth-next tree.