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Message-ID: <b5765f802e836641f41ff45f778d6901f4054050.camel@sipsolutions.net>
Subject: Re: [PATCH] mac80211: Add 802.11h CSA support
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Wen Gong <quic_wgong@quicinc.com>,
        Sujith <Sujith.Manoharan@atheros.com>, linville@tuxdriver.com
Cc:     linux-wireless@vger.kernel.org, Jouni.Malinen@Atheros.com,
        ath11k@lists.infradead.org
Date:   Tue, 22 Nov 2022 22:26:33 +0100
In-Reply-To: <04ad44c0-4012-50a4-f24a-64723a1c0a4f@quicinc.com>
References: <18786.55021.734826.472061@gargle.gargle.HOWL>
         <04ad44c0-4012-50a4-f24a-64723a1c0a4f@quicinc.com>
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On Wed, 2022-11-02 at 11:26 +0800, Wen Gong wrote:
> On 1/6/2009 11:58 AM, Sujith wrote:
> > Move to the advertised channel on reception of
> > a CSA element. This is needed for 802.11h compliance.
> >=20
> > Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
> > ---
> > v2
> > --
> > * Add a new variable to hold the CSA channel
> > * Use msecs_to_jiffies for calculating expiration time
> > * Add a check to drop beacons in case of a frequency mismatch
> >=20
> > v3
> > --
> > * Add a BSSID check when handling CSA action frame
> >=20
> >   net/mac80211/ieee80211_i.h |   11 ++++++-
> >   net/mac80211/iface.c       |    2 +
> >   net/mac80211/mlme.c        |   13 +++++++
> >   net/mac80211/rx.c          |   20 +++++++++++
> >   net/mac80211/spectmgmt.c   |   77 +++++++++++++++++++++++++++++++++++=
+++++++++
> >   5 files changed, 122 insertions(+), 1 deletions(-)
> >=20
> > ...
> > +void ieee80211_process_chanswitch(struct ieee80211_sub_if_data *sdata,
> > +				  struct ieee80211_channel_sw_ie *sw_elem,
> > +				  struct ieee80211_bss *bss)
> > +{
> > +	struct ieee80211_channel *new_ch;
> > +	struct ieee80211_if_sta *ifsta =3D &sdata->u.sta;
> > +	int new_freq =3D ieee80211_channel_to_frequency(sw_elem->new_ch_num);
> > +
> > +	/* FIXME: Handle ADHOC later */
> > +	if (sdata->vif.type !=3D NL80211_IFTYPE_STATION)
> > +		return;
> > +
> > +	if (ifsta->state !=3D IEEE80211_STA_MLME_ASSOCIATED)
> > +		return;
> > +
> > +	if (sdata->local->sw_scanning || sdata->local->hw_scanning)
> > +		return;
> > +
> May I know why channel switch should not go ahead while it is doing scan?

I don't remember, sorry.

johannes