tech@,

Here the next small bit of my iwx rework.

I follow iwlwifi and advertise RX antenna pattern only when RX is
effectively 1x1: there is one usable RX antenna, or MIMO is disabled.

OK?

Index: sys/dev/pci/if_iwx.c
===================================================================
RCS file: /home/cvs/src/sys/dev/pci/if_iwx.c,v
diff -u -p -r1.227 if_iwx.c
--- sys/dev/pci/if_iwx.c	1 Apr 2026 02:29:37 -0000	1.227
+++ sys/dev/pci/if_iwx.c	1 Apr 2026 21:55:11 -0000
@@ -3265,6 +3265,15 @@ iwx_setup_vht_rates(struct iwx_softc *sc
 	struct ieee80211com *ic = &sc->sc_ic;
 	uint8_t rx_ant = iwx_fw_valid_rx_ant(sc);
 	int n;
+	int num_rx_ant;
+
+	num_rx_ant = !!(rx_ant & IWX_ANT_A) + !!(rx_ant & IWX_ANT_B) +
+	    !!(rx_ant & IWX_ANT_C);
+
+	ic->ic_vhtcaps &= ~IEEE80211_VHTCAP_RX_ANT_PATTERN;
+
+	if (sc->sc_nvm.sku_cap_mimo_disable || num_rx_ant == 1)
+		ic->ic_vhtcaps |= IEEE80211_VHTCAP_RX_ANT_PATTERN;
 
 	ic->ic_vht_rxmcs = (IEEE80211_VHT_MCS_0_9 <<
 	    IEEE80211_VHT_MCS_FOR_SS_SHIFT(1));
@@ -12475,7 +12484,7 @@ iwx_attach(struct device *parent, struct
 	    (IEEE80211_VHTCAP_CHAN_WIDTH_160 <<
 		IEEE80211_VHTCAP_CHAN_WIDTH_SHIFT) |
 	    IEEE80211_VHTCAP_SGI80 | IEEE80211_VHTCAP_SGI160 |
-	    IEEE80211_VHTCAP_RX_ANT_PATTERN | IEEE80211_VHTCAP_TX_ANT_PATTERN;
+	    IEEE80211_VHTCAP_TX_ANT_PATTERN;
 
 	ic->ic_sup_rates[IEEE80211_MODE_11A] = ieee80211_std_rateset_11a;
 	ic->ic_sup_rates[IEEE80211_MODE_11B] = ieee80211_std_rateset_11b;