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Subject: Why does HT/VHT/HE/EHT depend on WMM?
From:   James Prestwood <prestwoj@gmail.com>
To:     linux-wireless@vger.kernel.org
Date:   Fri, 16 Dec 2022 16:17:33 -0800
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Hi,

I noticed this bit of code which disables HT/VHT/HE/EHT if the AP
doesn't support WMM:

net/mac80211/mlme.c:ieee80211_mgd_assoc()

/* also disable HT/VHT/HE/EHT if the AP doesn't use WMM */
if (!bss->wmm_used) {
	conn_flags |= IEEE80211_CONN_DISABLE_HT;
	conn_flags |= IEEE80211_CONN_DISABLE_VHT;
	conn_flags |= IEEE80211_CONN_DISABLE_HE;
	conn_flags |= IEEE80211_CONN_DISABLE_EHT;
	netdev_info(sdata->dev, "disabling HT/VHT/HE as WMM/QoS is not
supported by the AP\n");
}

It seems suspicious that 802.11 features would depend on a wifi-
alliance spec. Usually its the other way around.

I can see no such limitation set in 802.11 or the WMM spec, so I wonder
why this was done? If someone could educate me on why I'd be happy to
update the comment.

Thanks,
James