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Subject: Re: [PATCH] wifi: mac80211: Allow NSS change only up to capability
From:   Johannes Berg <johannes@sipsolutions.net>
To:     "Rameshkumar Sundaram (QUIC)" <quic_ramess@quicinc.com>
Cc:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Date:   Tue, 27 Dec 2022 16:42:48 +0100
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On Tue, 2022-12-27 at 08:04 +0000, Rameshkumar Sundaram (QUIC) wrote:
> >=20
> > > +		if (nss <=3D link_sta->pub->rx_nss) {
> > > +			link_sta->pub->rx_nss =3D nss;
> >=20
> > That, however, doesn't seem right. It means that you can only ever
> > reduce
> > the RX NSS, not switch it around within the originally negotiated
> > range.
> >=20
> Not sure if I understood you comment.
> We reset Sta's rx_nss

I don't see where it's being reset?

The way I'm reading this, you check nss<=3Drx_nss and then set rx_nss=3Dnss=
.
I didn't see any code that sets rx_nss higher, but maybe I missed it?

So if say rx_nss is 4, and nss is 2, then we set rx_nss to 2. But now if
the AP wants to switch back to 4, nss will be 4, rx_nss will be 2, and
the change is ignored, no?

johannes