Align HT protection flags we send to iwm(4) firmware with flags used by

Linux iwlwifi.

Setting the FAT protection flag while we're using 20 MHz channels doesn't
really make a lot of sense to me but apparently firmware expects it to be
set regardless. Linux does not use the SELF_CTS_EN flag so it might be better
to avoid using SELF_CTS_EN.

According to zxystd from OpenIntelWireless, the same change fixed fatal
firmware errors seen during HT protection updates for them:
https://github.com/OpenIntelWireless/itlwm/commit/032a14185a434b7181c0e78a953dc2e1c21a0853

test and ok gnezdo@

diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c
index f396e5d..9f46f25 100644 (file)
--- a/sys/dev/pci/if_iwm.c
+++ b/sys/dev/pci/if_iwm.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_iwm.c,v 1.331 2021/06/30 09:43:59 stsp Exp $       */
+/*     $OpenBSD: if_iwm.c,v 1.332 2021/06/30 09:44:56 stsp Exp $       */
 
 /*
  * Copyright (c) 2014, 2016 genua gmbh <info@genua.de>
@@ -7677,10 +7677,8 @@ iwm_mac_ctxt_cmd_common(struct iwm_softc *sc, struct iwm_node *in,
                case IEEE80211_HTPROT_NONMEMBER:
                case IEEE80211_HTPROT_NONHT_MIXED:
                        cmd->protection_flags |=
-                           htole32(IWM_MAC_PROT_FLG_HT_PROT);
-                       if (ic->ic_protmode == IEEE80211_PROT_CTSONLY)
-                               cmd->protection_flags |=
-                                   htole32(IWM_MAC_PROT_FLG_SELF_CTS_EN);
+                           htole32(IWM_MAC_PROT_FLG_HT_PROT |
+                           IWM_MAC_PROT_FLG_FAT_PROT);
                        break;
                case IEEE80211_HTPROT_20MHZ:
                        if (ic->ic_htcaps & IEEE80211_HTCAP_CBW20_40) {
@@ -7688,9 +7686,6 @@ iwm_mac_ctxt_cmd_common(struct iwm_softc *sc, struct iwm_node *in,
                                cmd->protection_flags |=
                                    htole32(IWM_MAC_PROT_FLG_HT_PROT |
                                    IWM_MAC_PROT_FLG_FAT_PROT);
-                               if (ic->ic_protmode == IEEE80211_PROT_CTSONLY)
-                                       cmd->protection_flags |= htole32(
-                                           IWM_MAC_PROT_FLG_SELF_CTS_EN);
                        }
                        break;
                default: