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

Export the non-shifted target_pf value to debugfs, so that it's human-readable.
Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

net/mac80211/rc80211_pid_algo.c

@@ -210,7 +210,7 @@ static void rate_control_pid_sample(struct rc_pid_info *pinfo,
 	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;