svn commit: r282704 - head/sys/net80211

[Adrian Chadd]

Author: adrian
Date: Sun May 10 06:57:53 2015
New Revision: 282704
URL: https://svnweb.freebsd.org/changeset/base/282704

Log:
  Attempt to address Bug #176201 - don't advertise what the AP announced
  to us. Instead, advertise what we can do based on what the AP says and what
  we're capped at by the VAP settings.
  
  For non-STA modes we still advertise what our VAP settings are.
  
  It may be that I've over-complicated this and instead of capping things
  we can just always announce what we're capable of.  But this should at least
  stop the blatantly wrong handling of A-MPDU parameters.
  
  (I'll happily simplify things if someone can dig up a replacement, better
  compliant behaviour.)
  
  PR:		kern/176201

Modified:
  head/sys/net80211/ieee80211_ht.c

Modified: head/sys/net80211/ieee80211_ht.c
==============================================================================
--- head/sys/net80211/ieee80211_ht.c	Sun May 10 04:33:01 2015	(r282703)
+++ head/sys/net80211/ieee80211_ht.c	Sun May 10 06:57:53 2015	(r282704)
@@ -2662,10 +2662,24 @@ ieee80211_add_htcap_body(uint8_t *frm, s
 			caps |= IEEE80211_HTCAP_CHWIDTH40;
 		else
 			caps &= ~IEEE80211_HTCAP_CHWIDTH40;
-		/* use advertised setting (XXX locally constraint) */
+
+		/* Start by using the advertised settings */
 		rxmax = MS(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU);
 		density = MS(ni->ni_htparam, IEEE80211_HTCAP_MPDUDENSITY);
 
+		/* Cap at VAP rxmax */
+		if (rxmax > vap->iv_ampdu_rxmax)
+			rxmax = vap->iv_ampdu_rxmax;
+
+		/*
+		 * If the VAP ampdu density value greater, use that.
+		 *
+		 * (Larger density value == larger minimum gap between A-MPDU
+		 * subframes.)
+		 */
+		if (vap->iv_ampdu_density > density)
+			density = vap->iv_ampdu_density;
+
 		/*
 		 * NB: Hardware might support HT40 on some but not all
 		 * channels. We can't determine this earlier because only
@@ -2682,9 +2696,12 @@ ieee80211_add_htcap_body(uint8_t *frm, s
 			caps |= IEEE80211_HTCAP_CHWIDTH40;
 		else
 			caps &= ~IEEE80211_HTCAP_CHWIDTH40;
+
+		/* XXX TODO should it start by using advertised settings? */
 		rxmax = vap->iv_ampdu_rxmax;
 		density = vap->iv_ampdu_density;
 	}
+
 	/* adjust short GI based on channel and config */
 	if ((vap->iv_flags_ht & IEEE80211_FHT_SHORTGI20) == 0)
 		caps &= ~IEEE80211_HTCAP_SHORTGI20;