rc80211-pid: export human-readable target_pf value to debugfs

Index: wireless-2.6/net/mac80211/rc80211_pid.h
===================================================================
@@ -38,7 +38,7 @@
  * link quality is good, the controller will fail to adjust failed frames
  * percentage to the target. This is intentional.
  */
-#define RC_PID_TARGET_PF (11 << RC_PID_ARITH_SHIFT)
+#define RC_PID_TARGET_PF 11
 
 /* Rate behaviour normalization quantity over time. */
 #define RC_PID_NORM_OFFSET 3

Index: wireless-2.6/net/mac80211/rc80211_pid_algo.c
===================================================================
@@ -210,7 +210,7 @@ static void rate_control_pid_sample(stru
 	rate_control_pid_normalize(pinfo, mode->num_rates);
 
 	/* Compute the proportional, integral and derivative errors. */
-	err_prop = pinfo->target - pf;
+	err_prop = (pinfo->target << RC_PID_ARITH_SHIFT) - pf;
 
 	err_avg = spinfo->err_avg_sc >> pinfo->smoothing_shift;
 	spinfo->err_avg_sc = spinfo->err_avg_sc - err_avg + err_prop;

Index: wireless-2.6/net/mac80211/rc80211_pid.h
===================================================================
@@ -1,5 +1,6 @@
 /*
  * Copyright 2007, Mattias Nissler <[email protected]>
+ * Copyright 2007, Stefano Brivio <[email protected]>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as

@@ -119,6 +120,29 @@ struct rc_pid_events_file_info {
 	unsigned int next_entry;
 };
 
+/**
+ * struct rc_pid_debugfs_entries - tunable parameters
+ *
+ * Algorithm parameters, tunable via debugfs.
+ * @dir: the debugfs directory for a specific phy
+ * @target: target percentage for failed frames
+ * @sampling_period: error sampling interval in milliseconds
+ * @coeff_p: absolute value of the proportional coefficient
+ * @coeff_i: absolute value of the integral coefficient
+ * @coeff_d: absolute value of the derivative coefficient
+ * @smoothing_shift: absolute value of the integral smoothing factor (i.e.
+ *	amount of smoothing introduced by the exponential moving average)
+ * @sharpen_factor: absolute value of the derivative sharpening factor (i.e.
+ *	amount of emphasis given to the derivative term after low activity
+ *	events)
+ * @sharpen_duration: duration of the sharpening effect after the detected low
+ *	activity event, relative to sampling_period
+ * @norm_offset: amount of normalization periodically performed on the learnt
+ *	rate behaviour values (lower means we should trust more what we learnt
+ *	about behaviour of rates, higher means we should trust more the natural
+ *	ordering of rates)
+ * @fast_start: if Y, push high rates right after initialization
+ */
 struct rc_pid_debugfs_entries {
 	struct dentry *dir;
 	struct dentry *target;

Index: wireless-2.6/net/mac80211/rc80211_pid_algo.c
===================================================================
@@ -74,29 +74,27 @@ static int rate_control_pid_shift_adjust
 {
 	int i, j, k, tmp;
 
-	if (cur + adj < 0)
-		return 0;
-	if (cur + adj >= l)
-		return l - 1;
+	j = r[cur].rev_index;
+	i = j + adj;
 
-	i = r[cur + adj].rev_index;
+	if (i < 0)
+		return r[0].index;
+	if (i >= l - 1)
+		return r[l - 1].index;
 
-	j = r[cur].rev_index;
+	tmp = i;
 
 	if (adj < 0) {
-			tmp = i;
-			for (k = j; k >= i; k--)
-				if (r[k].diff <= r[j].diff)
-					tmp = k;
-			return r[tmp].index;
-	} else if (adj > 0) {
-			tmp = i;
-			for (k = i + 1; k + i < l; k++)
-				if (r[k].diff <= r[i].diff)
-					tmp = k;
-			return r[tmp].index;
+		for (k = j; k >= i; k--)
+			if (r[k].diff <= r[j].diff)
+				tmp = k;
+	} else {
+		for (k = i + 1; k + i < l; k++)
+			if (r[k].diff <= r[i].diff)
+				tmp = k;
 	}
-	return cur + adj;
+
+	return r[tmp].index;
 }
 
 static void rate_control_pid_adjust_rate(struct ieee80211_local *local,

Index: wireless-2.6/net/mac80211/rc80211_pid_algo.c
===================================================================
@@ -254,7 +254,7 @@ static void rate_control_pid_tx_status(v
 	/* Ignore all frames that were sent with a different rate than the rate
 	 * we currently advise mac80211 to use. */
 	if (status->control.rate != &local->oper_hw_mode->rates[sta->txrate])
-		return;
+		goto ignore;
 
 	spinfo = sta->rate_ctrl_priv;
 	spinfo->tx_num_xmit++;

@@ -295,6 +295,7 @@ static void rate_control_pid_tx_status(v
 	if (time_after(jiffies, spinfo->last_sample + period))
 		rate_control_pid_sample(pinfo, local, sta);
 
+ignore:
 	sta_info_put(sta);
 }
 

Index: wireless-2.6/net/mac80211/rc80211_pid.h
===================================================================
@@ -11,41 +11,41 @@
 #define RC80211_PID_H
 
 /* Sampling period for measuring percentage of failed frames. */
-#define RC_PID_INTERVAL (HZ / 8)
+#define RC_PID_INTERVAL			(HZ / 8)
 
 /* Exponential averaging smoothness (used for I part of PID controller) */
-#define RC_PID_SMOOTHING_SHIFT 3
-#define RC_PID_SMOOTHING (1 << RC_PID_SMOOTHING_SHIFT)
+#define RC_PID_SMOOTHING_SHIFT		3
+#define RC_PID_SMOOTHING		(1 << RC_PID_SMOOTHING_SHIFT)
 
 /* Sharpening factor (used for D part of PID controller) */
-#define RC_PID_SHARPENING_FACTOR 0
-#define RC_PID_SHARPENING_DURATION 0
+#define RC_PID_SHARPENING_FACTOR	0
+#define RC_PID_SHARPENING_DURATION	0
 
 /* Fixed point arithmetic shifting amount. */
-#define RC_PID_ARITH_SHIFT 8
+#define RC_PID_ARITH_SHIFT		8
 
 /* Fixed point arithmetic factor. */
-#define RC_PID_ARITH_FACTOR (1 << RC_PID_ARITH_SHIFT)
+#define RC_PID_ARITH_FACTOR		(1 << RC_PID_ARITH_SHIFT)
 
 /* Proportional PID component coefficient. */
-#define RC_PID_COEFF_P 15
+#define RC_PID_COEFF_P			15
 /* Integral PID component coefficient. */
-#define RC_PID_COEFF_I 9
+#define RC_PID_COEFF_I			9
 /* Derivative PID component coefficient. */
-#define RC_PID_COEFF_D 15
+#define RC_PID_COEFF_D			15
 
 /* Target failed frames rate for the PID controller. NB: This effectively gives
  * maximum failed frames percentage we're willing to accept. If the wireless
  * link quality is good, the controller will fail to adjust failed frames
  * percentage to the target. This is intentional.
  */
-#define RC_PID_TARGET_PF 11
+#define RC_PID_TARGET_PF		14
 
 /* Rate behaviour normalization quantity over time. */
-#define RC_PID_NORM_OFFSET 3
+#define RC_PID_NORM_OFFSET		3
 
 /* Push high rates right after loading. */
-#define RC_PID_FAST_START 0
+#define RC_PID_FAST_START		0
 
 /* Arithmetic right shift for positive and negative values for ISO C. */
 #define RC_PID_DO_ARITH_RIGHT_SHIFT(x, y) \

Index: wireless-2.6/net/mac80211/sta_info.c
===================================================================
@@ -105,6 +105,7 @@ static void sta_info_release(struct kref
 	struct ieee80211_local *local = sta->local;
 	struct sk_buff *skb;
 
+	write_lock_bh(&local->sta_lock);
 	/* free sta structure; it has already been removed from
 	 * hash table etc. external structures. Make sure that all
 	 * buffered frames are release (one might have been added

@@ -118,6 +119,8 @@ static void sta_info_release(struct kref
 	}
 	rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
 	rate_control_put(sta->rate_ctrl);
+	write_unlock_bh(&local->sta_lock);
+
 	kfree(sta);
 }