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Date: Fri, 7 Jun 2024 12:15:24 +0530
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Subject: Re: [RFC v3 4/8] wifi: mac80211: add support for DFS with multiple
 radios
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To: Felix Fietkau <nbd@nbd.name>, <linux-wireless@vger.kernel.org>
CC: <johannes@sipsolutions.net>, <quic_adisi@quicinc.com>,
        <ath12k@lists.infradead.org>
References: <cover.386a66ec6a89750d4890f63f0d28582a52b838b5.1717696995.git-series.nbd@nbd.name>
 <7cc3d89225f365c85b363874725cfbc77c9c1db5.1717696995.git-series.nbd@nbd.name>
 <2014e488-b930-43ff-86a6-c5a4801b82f5@quicinc.com>
 <21956735-3a04-4f29-8f13-0f84ed93cda2@nbd.name>
 <cdf2d06a-4d06-df69-245b-fc9ece0c1f2b@quicinc.com>
 <da6038ed-87f8-40ec-a327-6065334097af@nbd.name>
From: Karthikeyan Periyasamy <quic_periyasa@quicinc.com>
In-Reply-To: <da6038ed-87f8-40ec-a327-6065334097af@nbd.name>
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On 6/7/2024 10:33 AM, Felix Fietkau wrote:
> On 07.06.24 06:54, Karthikeyan Periyasamy wrote:
>>
>>
>> On 6/7/2024 10:05 AM, Felix Fietkau wrote:
>>> On 07.06.24 06:25, Karthikeyan Periyasamy wrote:
>>>>
>>>>
>>>> On 6/6/2024 11:37 PM, Felix Fietkau wrote:
>>>>> DFS can be supported with multi-channel combinations, as long as 
>>>>> each DFS
>>>>> capable radio only supports one channel.
>>>>>
>>>>> Signed-off-by: Felix Fietkau <nbd@nbd.name>
>>>>> ---
>>>>>   net/mac80211/main.c | 32 ++++++++++++++++++++++++--------
>>>>>   1 file changed, 24 insertions(+), 8 deletions(-)
>>>>>
>>>>> diff --git a/net/mac80211/main.c b/net/mac80211/main.c
>>>>> index 40fbf397ce74..e9c4cf611e94 100644
>>>>> --- a/net/mac80211/main.c
>>>>> +++ b/net/mac80211/main.c
>>>>
>>>> ...
>>>>
>>>>>   int ieee80211_register_hw(struct ieee80211_hw *hw)
>>>>>   {
>>>>>       struct ieee80211_local *local = hw_to_local(hw);
>>>>> @@ -1173,17 +1188,18 @@ int ieee80211_register_hw(struct 
>>>>> ieee80211_hw *hw)
>>>>>               if (comb->num_different_channels > 1)
>>>>>                   return -EINVAL;
>>>>>           }
>>>>> -    } else {
>>>>> -        /* DFS is not supported with multi-channel combinations 
>>>>> yet */
>>>>> -        for (i = 0; i < local->hw.wiphy->n_iface_combinations; i++) {
>>>>> -            const struct ieee80211_iface_combination *comb;
>>>>> -
>>>>> -            comb = &local->hw.wiphy->iface_combinations[i];
>>>>> +    } else if (hw->wiphy->n_radio) {
>>>>> +        for (i = 0; i < hw->wiphy->n_radio; i++) {
>>>>> +            const struct wiphy_radio *radio = &hw->wiphy->radio[i];
>>>>> -            if (comb->radar_detect_widths &&
>>>>> -                comb->num_different_channels > 1)
>>>>> +            if 
>>>>> (!ieee80211_ifcomb_check_radar(radio->iface_combinations,
>>>>> +                              radio->n_iface_combinations))
>>>>>                   return -EINVAL;
>>>>>           }
>>>>> +    } else {
>>>>> +        if 
>>>>> (!ieee80211_ifcomb_check_radar(hw->wiphy->iface_combinations,
>>>>> +                          hw->wiphy->n_iface_combinations))
>>>>> +            return -EINVAL;
>>>>>       }
>>>>>       /* Only HW csum features are currently compatible with 
>>>>> mac80211 */
>>>>
>>>> Are we omitting the "wiphy->iface_combinations" if the radio specific
>>>> iface combination advertised ?
>>>>
>>>> If so, it looks like unused "wiphy->iface_combinations" for radio
>>>> specific combination advertised.
>>>
>>> This patch series assumes that you have both 
>>> wiphy->iface_combinations and radio->iface_combinations set. 
>>> wiphy->iface_combinations applies to the full wiphy, whereas 
>>> radio->iface_combinations only applies to vifs assigned to the radio.
>>
>>
>> If radio->iface_combinations is set then always vifs assigned to the
>> radio. so wiphy->iface_combinations get avoid for all the use cases.
>>
>> Ultimately either of one combination only get used by this proposal.
>>
>> or I am missing something here ?
> 
> The functions that perform interface combination checks are called both 
> with -1 as radio_idx (meaning per-wiphy), as well as with the assigned 
> radio id. That way, both kinds of combinations/limits are checked and 
> enforced.
> 
In the radio specific iface advertisement, global iface combination 
represent the union or intersection of all radio iface combination ?

-- 
Karthikeyan Periyasamy
--
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