My rev 83 "MLD" firmware iwx(4) doesn't work as well at home as it did
in the hackroom in Valencia.  There is significant packet loss.  So I
started looking again at the new code to see if I missed some things.
One thing I missed is correctly setting the AMDPU density parameter.

I also noticed that the Linux driver uses a larger maximum aggregation
length with a not that this is the maximum size supported by the
firmware.  So I bumped that too.

I also fixed a missing htole32(), although that will make not
difference on amd64.

The diff doesn't completely fix things; there is still significant
packet loss (also in non-HT mode).  But it appears to make thuiings a
little bit better.

ok?


Index: dev/pci/if_iwx.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/if_iwx.c,v
retrieving revision 1.189
diff -u -p -r1.189 if_iwx.c
--- dev/pci/if_iwx.c	4 Feb 2025 09:15:04 -0000	1.189
+++ dev/pci/if_iwx.c	23 Feb 2025 12:26:47 -0000
@@ -6912,8 +6912,8 @@ iwx_mld_add_sta_cmd(struct iwx_softc *sc
 	struct ieee80211com *ic = &sc->sc_ic;
 	struct iwx_link_config_cmd link_cmd;
 	struct iwx_mvm_sta_cfg_cmd sta_cmd;
-	uint32_t aggsize;
-	const uint32_t max_aggsize = (IWX_STA_FLG_MAX_AGG_SIZE_64K >>
+	uint32_t aggsize, mpdu_dens;
+	const uint32_t max_aggsize = (IWX_STA_FLG_MAX_AGG_SIZE_4M >>
 		    IWX_STA_FLG_MAX_AGG_SIZE_SHIFT);
 	int err, changes;
 
@@ -6970,6 +6970,9 @@ iwx_mld_add_sta_cmd(struct iwx_softc *sc
 		if (iwx_mimo_enabled(sc))
 			sta_cmd.mimo = htole32(1);
 
+		mpdu_dens = (in->in_ni.ni_ampdu_param &
+		    IEEE80211_AMPDU_PARAM_SS) >> 2;
+
 		if (in->in_ni.ni_flags & IEEE80211_NODE_VHT) {
 			aggsize = (in->in_ni.ni_vhtcaps &
 			    IEEE80211_VHTCAP_MAX_AMPDU_LEN_MASK) >>
@@ -6981,8 +6984,8 @@ iwx_mld_add_sta_cmd(struct iwx_softc *sc
 		if (aggsize > max_aggsize)
 			aggsize = max_aggsize;
 
-		sta_cmd.tx_ampdu_spacing = htole32(0);
-		sta_cmd.tx_ampdu_max_size = aggsize;
+		sta_cmd.tx_ampdu_spacing = htole32(mpdu_dens);
+		sta_cmd.tx_ampdu_max_size = htole32(aggsize);
 	}
 
 	return iwx_send_cmd_pdu(sc,