Re: Adhoc networking, was Re: compat-wireless and minstrel

[Adam Wozniak <awozniak@irobot.com>]

Johannes Berg wrote:
> No, point a) is incorrect -- it is the _basic_ rate set only, not the
> entire rate set. Hence not knowing which rates a station actually
> supports.
>   
In either case, having minstrel use all rates doesn't seem like it 
should hurt much.  This is the patch I'm running with now, and it seems 
to work.  The changes in ibss.c make sure supp_rates is initialized 
properly, and that rate control is called when a change occurs.  If 
other stuff is working right (?) this should help PID and other rate 
control algorithms.  The changes in rc80211_minstrel.c make it ignore 
the supported rates set and just try everything.


diff -upr compat-wireless-2009-11-17/net/mac80211/ibss.c 
compat-wireless-2009-11-17a/net/mac80211/ibss.c
--- compat-wireless-2009-11-17/net/mac80211/ibss.c    2009-11-16 
21:17:21.000000000 -0800
+++ compat-wireless-2009-11-17a/net/mac80211/ibss.c    2009-11-17 
09:01:54.287720290 -0800
@@ -246,9 +246,13 @@ static void ieee80211_rx_bss_info(struct
     if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
         return;
 
+    supp_rates = ieee80211_sta_get_rates(local, elems, band);
+
+    /* make sure mandatory rates are always added */
+    supp_rates |= ieee80211_mandatory_rates(local, band);
+
     if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
         memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
-        supp_rates = ieee80211_sta_get_rates(local, elems, band);
 
         rcu_read_lock();
 
@@ -257,12 +261,10 @@ static void ieee80211_rx_bss_info(struct
             u32 prev_rates;
 
             prev_rates = sta->sta.supp_rates[band];
-            /* make sure mandatory rates are always added */
-            sta->sta.supp_rates[band] = supp_rates |
-                ieee80211_mandatory_rates(local, band);
+            sta->sta.supp_rates[band] = supp_rates;
 
+            if (sta->sta.supp_rates[band] != prev_rates) {
 #ifdef CONFIG_MAC80211_IBSS_DEBUG
-            if (sta->sta.supp_rates[band] != prev_rates)
                 printk(KERN_DEBUG "%s: updated supp_rates set "
                     "for %pM based on beacon info (0x%llx | "
                     "0x%llx -> 0x%llx)\n",
@@ -272,6 +274,8 @@ static void ieee80211_rx_bss_info(struct
                     (unsigned long long) supp_rates,
                     (unsigned long long) sta->sta.supp_rates[band]);
 #endif
+                rate_control_rate_init(sta);
+            }
         } else
             ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 
supp_rates);
 
@@ -415,6 +419,15 @@ struct sta_info *ieee80211_ibss_add_sta(
     sta->sta.supp_rates[band] = supp_rates |
             ieee80211_mandatory_rates(local, band);
 
+#ifdef CONFIG_MAC80211_IBSS_DEBUG
+    printk(KERN_DEBUG "%s: initialized supp_rates set "
+        "for %pM (0x%llx) (band %d)\n",
+        sdata->dev->name,
+        sta->sta.addr,
+        (unsigned long long) sta->sta.supp_rates[band],
+        band);
+#endif
+
     rate_control_rate_init(sta);
 
     if (sta_info_insert(sta))
diff -upr compat-wireless-2009-11-17/net/mac80211/rc80211_minstrel.c 
compat-wireless-2009-11-17a/net/mac80211/rc80211_minstrel.c
--- compat-wireless-2009-11-17/net/mac80211/rc80211_minstrel.c    
2009-11-16 21:17:21.000000000 -0800
+++ compat-wireless-2009-11-17a/net/mac80211/rc80211_minstrel.c    
2009-11-17 09:02:25.544628968 -0800
@@ -395,8 +395,6 @@ minstrel_rate_init(void *priv, struct ie
         unsigned int tx_time_single;
         unsigned int cw = mp->cw_min;
 
-        if (!rate_supported(sta, sband->band, i))
-            continue;
         n++;
         memset(mr, 0, sizeof(*mr));