MateuszPiotrowski/Drivers/FreeBSD

Contents

What's missing from iwm?
What's already there?
Related files in the source tree
FreeBSD networking stack

What's missing from iwm?

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

MIMO

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):

```
   1 static int
   2 iwm_mvm_sta_send_to_fw(struct iwm_softc *sc, struct iwm_node *in, int update)
   3 {
   4         /* ... */
   5         add_sta_cmd.station_flags_msk
   6             |= 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:

   1 static void
   2 iwm_setrates(struct iwm_softc *sc, struct iwm_node *in)
   3 {
   4         /* ... */
   5         /*
   6          * are these used? (we don't do SISO or MIMO)
   7          * need to set them to non-zero, though, or we get an error.
   8          */
   9         lq->single_stream_ant_msk = 1;
  10         lq->dual_stream_ant_msk = 1;

No, iwm does not support MIMO yet:

   1 static void
   2 iwm_mvm_fill_sf_command(struct iwm_softc *sc, struct iwm_sf_cfg_cmd *sf_cmd,
   3     struct ieee80211_node *ni)
   4 {
   5         /* ... */
   6 #ifdef notyet
   7                         if (ni->ni_rxmcs[2] != 0)
   8                                 watermark = IWM_SF_W_MARK_MIMO3;
   9                         else if (ni->ni_rxmcs[1] != 0)
  10                                 watermark = IWM_SF_W_MARK_MIMO2;
  11                         else
  12 #endif
  13

11n support

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

From WiFi/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