• iwm needs fixing in how it interacts with the net80211 state machine (for associating/disassociating with access points and so on).

• iwm is not loaded automatically during installation

• See TODO list on WiFi

OpenBSD-current should have MIMO support although it hasn't been tested by Imre personally.

There is an IWM_STA_FLG_MIMO_EN_MSK flag in if_iwmreg.h which if set means that a device has a support for MIMO. Here's a part of the if_iwm.c suggesting that MIMO is supported (MIMO is not supported yet, it is just a flag):

static int
iwm_mvm_sta_send_to_fw(struct iwm_softc *sc, struct iwm_node *in, int update)
{
	/* ... */
	add_sta_cmd.station_flags_msk
	    |= htole32(IWM_STA_FLG_FAT_EN_MSK | IWM_STA_FLG_MIMO_EN_MSK);

On the other hand we later read in the same file that:

static void
iwm_setrates(struct iwm_softc *sc, struct iwm_node *in)
{
	/* ... */
	/*
	 * are these used? (we don't do SISO or MIMO)
	 * need to set them to non-zero, though, or we get an error.
	 */
	lq->single_stream_ant_msk = 1;
	lq->dual_stream_ant_msk = 1;

No, iwm does not support MIMO yet:

static void
iwm_mvm_fill_sf_command(struct iwm_softc *sc, struct iwm_sf_cfg_cmd *sf_cmd,
    struct ieee80211_node *ni)
{
	/* ... */
#ifdef notyet
			if (ni->ni_rxmcs[2] != 0)
				watermark = IWM_SF_W_MARK_MIMO3;
			else if (ni->ni_rxmcs[1] != 0)
				watermark = IWM_SF_W_MARK_MIMO2;
			else
#endif

OpenBSD-stable has basic 11n support in iwm thanks to Stefan Sperling (stsp at OpenBSD).

From 80211n:

• 802.11n LDPC encoding
• 802.11n DFS support - the current support only functions with 802.11a channels
• 802.11n rate control/selection in net80211 - currently, the rate control modules in net80211 only know about legacy rates

WiFi suggests that 11ac is barely (or not at all) supported in FreeBSD

Things needed for 11ac support in FreeBSD: FixUpThings

802.11ac TODO list: 80211ac

• Networking

• 11a, 11bg support: https://lists.freebsd.org/pipermail/freebsd-wireless/2017-March/007552.html

sys/dev/iwm
sys/net80211

• ifnet(9): https://www.freebsd.org/cgi/man.cgi?query=ifnet&sektion=9&apropos=0&manpath=FreeBSD+11.0-RELEASE+and+Ports

indicates that I've not read it yet (and most often just scanned through)
indicates that I've got to investigate whether it is true or not

Special thanks to