Re: [PATCH v1 1/5] Bluetooth: advmon offload MSFT add rssi support

[Marcel Holtmann]

Hi Archie,

>>>>> MSFT needs rssi parameter for monitoring advertisement packet,
>>>>> therefore we should supply them from mgmt.
>>>>> 
>>>>> Signed-off-by: Archie Pusaka <apusaka@xxxxxxxxxxxx>
>>>>> Reviewed-by: Miao-chen Chou <mcchou@xxxxxxxxxxxx>
>>>>> Reviewed-by: Yun-Hao Chung <howardchung@xxxxxxxxxx>
>>>> 
>>>> I don’t need any Reviewed-by if they are not catching an obvious user API breakage.
>>>> 
>>>>> ---
>>>>> 
>>>>> include/net/bluetooth/hci_core.h | 9 +++++++++
>>>>> include/net/bluetooth/mgmt.h     | 9 +++++++++
>>>>> net/bluetooth/mgmt.c             | 8 ++++++++
>>>>> 3 files changed, 26 insertions(+)
>>>>> 
>>>>> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
>>>>> index 9873e1c8cd16..42d446417817 100644
>>>>> --- a/include/net/bluetooth/hci_core.h
>>>>> +++ b/include/net/bluetooth/hci_core.h
>>>>> @@ -246,8 +246,17 @@ struct adv_pattern {
>>>>>     __u8 value[HCI_MAX_AD_LENGTH];
>>>>> };
>>>>> 
>>>>> +struct adv_rssi_thresholds {
>>>>> +     __s8 low_threshold;
>>>>> +     __s8 high_threshold;
>>>>> +     __u16 low_threshold_timeout;
>>>>> +     __u16 high_threshold_timeout;
>>>>> +     __u8 sampling_period;
>>>>> +};
>>>>> +
>>>>> struct adv_monitor {
>>>>>     struct list_head patterns;
>>>>> +     struct adv_rssi_thresholds rssi;
>>>>>     bool            active;
>>>>>     __u16           handle;
>>>>> };
>>>>> diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
>>>>> index d8367850e8cd..dc534837be0e 100644
>>>>> --- a/include/net/bluetooth/mgmt.h
>>>>> +++ b/include/net/bluetooth/mgmt.h
>>>>> @@ -763,9 +763,18 @@ struct mgmt_adv_pattern {
>>>>>     __u8 value[31];
>>>>> } __packed;
>>>>> 
>>>>> +struct mgmt_adv_rssi_thresholds {
>>>>> +     __s8 high_threshold;
>>>>> +     __le16 high_threshold_timeout;
>>>>> +     __s8 low_threshold;
>>>>> +     __le16 low_threshold_timeout;
>>>>> +     __u8 sampling_period;
>>>>> +} __packed;
>>>>> +
>>>>> #define MGMT_OP_ADD_ADV_PATTERNS_MONITOR      0x0052
>>>>> struct mgmt_cp_add_adv_patterns_monitor {
>>>>>     __u8 pattern_count;
>>>>> +     struct mgmt_adv_rssi_thresholds rssi;
>>>>>     struct mgmt_adv_pattern patterns[];
>>>>> } __packed;
>>>> 
>>>> This is something we can not do. It breaks an userspace facing API. Is the mgmt opcode 0x0052 in an already released kernel?
>>> 
>>> Yes, the opcode does exist in an already released kernel.
>>> 
>>> The DBus method which accesses this API is put behind the experimental
>>> flag, therefore we expect they are flexible enough to support changes.
>>> Previously, we already had a discussion in an email thread with the
>>> title "Offload RSSI tracking to controller", and the outcome supports
>>> this change.
>>> 
>>> Here is an excerpt of the discussion.
>> 
>> it doesn’t matter. This is fixed API now and so we can not just change it. The argument above is void. What matters if it is in already released kernel.
> 
> If that is the case, do you have a suggestion to allow RSSI to be
> considered when monitoring advertisement? Would a new MGMT opcode with
> these parameters suffice?

its the only way.

Regards

Marcel