git: 363846a7e31b - main - net80211: fix VHT80/VHT160 transmit width checks

The branch main has been updated by adrian:

URL: https://cgit.FreeBSD.org/src/commit/?id=363846a7e31b013dc7ebccd8017578fe79ee5103

commit 363846a7e31b013dc7ebccd8017578fe79ee5103
Author:     Adrian Chadd <adrian@FreeBSD.org>
AuthorDate: 2025-05-01 04:09:52 +0000
Commit:     Adrian Chadd <adrian@FreeBSD.org>
CommitDate: 2025-05-03 15:38:25 +0000

    net80211: fix VHT80/VHT160 transmit width checks
    
    I didn't double check to see if ni_chw had been updated to actually
    implement values other than 20/40.  It's just implementing the
    HT channel width stuff during both association and upon receiving
    a HT TX channel width action frame.
    
    This meant the VHT80/VHT160 transmit width checks were never
    going to be true, as ni_chw is never set to VHT80 / VHT160.
    
    After checking the HT action frame and looking for VHT changes,
    I'm pretty sure there's nothing explicit about VHT width, as it's
    normally done via CCA (clear channel access) and/or RTS/CTS exchanges -
    each 20MHz subchannel is RTS/CTS'ed / will be checked and if they're
    busy, a narrower frame will be transmitted.
    
    So, change the VHT80 / VHT160 checks to only check if ni_chw is 20MHz.
    If it's 20MHz then a HT action frame has come out saying to TX at 20MHz,
    and we should obey it.  Otherwise, do 80/160MHz as available.
    
    Differential Revision:  https://reviews.freebsd.org/D50096
    Reviewed by:    bz
---
 sys/net80211/ieee80211_vht.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/sys/net80211/ieee80211_vht.c b/sys/net80211/ieee80211_vht.c
index 0df95d87d01a..eb4ea615da75 100644
--- a/sys/net80211/ieee80211_vht.c
+++ b/sys/net80211/ieee80211_vht.c
@@ -992,9 +992,15 @@ ieee80211_vht_check_tx_vht80(const struct ieee80211_node *ni)
 	vap = ni->ni_vap;
 	bss_chan = vap->iv_bss->ni_chan;
 
+	/*
+	 * ni_chw represents 20MHz or 40MHz from the HT
+	 * TX width action frame / HT channel negotiation.
+	 * If a HT TX width action frame sets it to 20MHz
+	 * then reject doing 80MHz.
+	 */
 	return (IEEE80211_IS_CHAN_VHT80(bss_chan) &&
 	    IEEE80211_IS_CHAN_VHT80(ni->ni_chan) &&
-	    (ni->ni_chw == IEEE80211_STA_RX_BW_80));
+	    (ni->ni_chw != IEEE80211_STA_RX_BW_20));
 }
 
 /*
@@ -1015,7 +1021,13 @@ ieee80211_vht_check_tx_vht160(const struct ieee80211_node *ni)
 	vap = ni->ni_vap;
 	bss_chan = vap->iv_bss->ni_chan;
 
-	if (ni->ni_chw != IEEE80211_STA_RX_BW_160)
+	/*
+	 * ni_chw represents 20MHz or 40MHz from the HT
+	 * TX width action frame / HT channel negotiation.
+	 * If a HT TX width action frame sets it to 20MHz
+	 * then reject doing 160MHz.
+	 */
+	if (ni->ni_chw == IEEE80211_STA_RX_BW_20)
 		return (false);
 
 	if (IEEE80211_IS_CHAN_VHT160(bss_chan) &&