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Message-ID: <37a24557-2562-4891-e7ec-18b5527a54f0@candelatech.com>
Date:   Wed, 9 Aug 2023 12:32:19 -0700
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Subject: Re: [PATCH v2] wifi: mac80211: add eht_capa debugfs field.
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To:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org
References: <20230519162324.1633120-1-greearb@candelatech.com>
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From:   Ben Greear <greearb@candelatech.com>
Organization: Candela Technologies
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On 6/14/23 13:08, Johannes Berg wrote:
> On Wed, 2023-06-14 at 09:39 -0700, Ben Greear wrote:
>> On 6/14/23 01:29, Johannes Berg wrote:
>>>
>>>> +	/* TODO:  Fix and re-add this.  It compiles in 6.4 but not against 'next'
>>>> +	 * according to the kernel build bot.
>>>> +	 * PFLAG(PHY, 5, SUPP_EXTRA_EHT_LTF, "SUPP-EXTRA-EHT-LTF");
>>>> +	 */
>>>>
>>>
>>> Well that's because the spec version was updated in wireless-next :)
>>>
>>> So please adjust according to the new fields there.
>>
>> It will be some time before I get a chance to revisit this.  If you can
>> accept as is, I'll fix the remaining bits when I move to 6.5 or whatever
>> mainline kernel has the updated spec.
>>
> 
> Actually I think it was just this field, so maybe I can just take v1.

After doing some more detailed testing, I notice that this capa logic is using
the AP's capability list, and is not showing lowest common features.  For instance,
a 2x2 STA radio shows as this when connected to 4x4 AP:

...
		EHT bw <= 80 MHz, max NSS for MCS 8-9: Rx=4, Tx=4
		EHT bw <= 80 MHz, max NSS for MCS 10-11: Rx=4, Tx=4
		EHT bw <= 80 MHz, max NSS for MCS 12-13: Rx=4, Tx=4
		EHT bw <= 160 MHz, max NSS for MCS 8-9: Rx=4, Tx=4
		EHT bw <= 160 MHz, max NSS for MCS 10-11: Rx=4, Tx=4
		EHT bw <= 160 MHz, max NSS for MCS 12-13: Rx=4, Tx=4
		EHT bw <= 320 MHz, max NSS for MCS 8-9: Rx=4, Tx=4
		EHT bw <= 320 MHz, max NSS for MCS 10-11: Rx=4, Tx=4
		EHT bw <= 320 MHz, max NSS for MCS 12-13: Rx=4, Tx=4

I would expect it to show Rx=2, Tx=2 in this case.

Any opinions on how or whether to change this?  Do we already store a combined
capabilities list somewhere in mac80211 for EHT?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com