Message-ID: <175755ef-e9b3-b039-0874-4a0bfb6eac2b@quicinc.com>
Date:   Wed, 15 Feb 2023 09:56:43 +0800
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Subject: Re: [PATCH v10 3/5] cfg80211/mac80211: move interface counting for
 combination check to mac80211
Content-Language: en-US
To:     Johannes Berg <johannes@sipsolutions.net>,
        Luciano Coelho <luciano.coelho@intel.com>,
        <linux-wireless@vger.kernel.org>
CC:     <michal.kazior@tieto.com>, <sw@simonwunderlich.de>,
        <andrei.otcheretianski@intel.com>, <eliad@wizery.com>,
        <ath11k@lists.infradead.org>
References: <1394547394-3910-1-git-send-email-luciano.coelho@intel.com>
 <1394547394-3910-4-git-send-email-luciano.coelho@intel.com>
 <4de1f964-b623-2b31-c044-60cc188fc134@quicinc.com>
 <6187b1566674ba2e0d7d5413af5475688d8421b3.camel@sipsolutions.net>
 <6c2b5e49-2cdc-b506-e3c8-0a51fccc294d@quicinc.com>
 <f5ffcc0b186cf9285e1dedebc8cf47c06d46bbd9.camel@sipsolutions.net>
From:   Wen Gong <quic_wgong@quicinc.com>
In-Reply-To: <f5ffcc0b186cf9285e1dedebc8cf47c06d46bbd9.camel@sipsolutions.net>
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On 2/14/2023 10:41 PM, Johannes Berg wrote:
> On Tue, 2023-01-10 at 15:23 +0800, Wen Gong wrote:
>> On 1/9/2023 6:05 PM, Johannes Berg wrote:
>>> On Mon, 2023-01-09 at 17:39 +0800, Wen Gong wrote:
>>>> On 3/11/2014 10:16 PM, Luciano Coelho wrote:
>>>>> ...
>>>>> +int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
>>>>> +				 const struct cfg80211_chan_def *chandef,
>>>>> +				 enum ieee80211_chanctx_mode chanmode,
>>>>> +				 u8 radar_detect)
>> ...
>>>>> +
>>>>> +	if (total == 1 && !radar_detect)
>>>>> +		return 0;
>>>>> +
>>>> should also check with cfg80211_check_combinations() when total == 1 and
>>>> num_different_channels > 1 ?
>>>>
>>>> When MLO is enabled, it could have 2 channels for one ieee80211_sub_if_data.
>>>>
>>> Heh. You're commenting on a patch from 2014, well before MLO :-)
>>>
>>> Not sure what happens in the code now?
>>>
>>> johannes
>> Yes, it is 2014. Each interface only has one channel at 2014.
>> I did not hit issue for the code.
>>
>> the story is like this:
>> When station interface and p2p device interface both running.
>> the station connect to MLO AP which has 2 links.
>> The ieee80211_link_use_channel()/ieee80211_check_combinations() call
>> cfg80211_check_combinations()
>> for the channel1 and channel2 because total==2.
>> When only station interface is running, not called for channel1/channel2
>> because total==1.
>> That is the little thing I hit.
>>
> So ... I guess you found a bug? Not sure what I'm supposed to say here.
> Send a fix?
I consider it NOT a bug. It is only the check is not strict here.
>
> johannes