am 81931b8b: Increase channel delay to 100ms

[android-x86/external-wpa_supplicant_8.git] / wpa_supplicant / bgscan_simple.c

diff --git a/wpa_supplicant/bgscan_simple.c b/wpa_supplicant/bgscan_simple.c
index eedc961..479f703 100644 (file)
--- a/wpa_supplicant/bgscan_simple.c
+++ b/wpa_supplicant/bgscan_simple.c
@@ -2,14 +2,8 @@
  * WPA Supplicant - background scan and roaming module: simple
  * Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
  *
- * 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
- * published by the Free Software Foundation.
- *
- * Alternatively, this software may be distributed under the terms of BSD
- * license.
- *
- * See README and COPYING for more details.
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
  */
 
 #include "includes.h"
@@ -29,6 +23,7 @@ struct bgscan_simple_data {
        int scan_interval;
        int signal_threshold;
        int short_scan_count; /* counter for scans using short scan interval */
+       int max_short_scans; /* maximum times we short-scan before back-off */
        int short_interval; /* use if signal < threshold */
        int long_interval; /* use if signal > threshold */
        struct os_time last_bgscan;
@@ -66,12 +61,19 @@ static void bgscan_simple_timeout(void *eloop_ctx, void *timeout_ctx)
                         * scanning at the short scan interval. After that,
                         * revert to the long scan interval.
                         */
-                       if (data->short_scan_count >
-                           data->long_interval / data->short_interval + 1) {
+                       if (data->short_scan_count > data->max_short_scans) {
                                data->scan_interval = data->long_interval;
                                wpa_printf(MSG_DEBUG, "bgscan simple: Backing "
                                           "off to long scan interval");
                        }
+               } else if (data->short_scan_count > 0) {
+                       /*
+                        * If we lasted a long scan interval without any
+                        * CQM triggers, decrease the short-scan count,
+                        * which allows 1 more short-scan interval to
+                        * occur in the future when CQM triggers.
+                        */
+                       data->short_scan_count--;
                }
                os_get_time(&data->last_bgscan);
        }
@@ -138,6 +140,7 @@ static void * bgscan_simple_init(struct wpa_supplicant *wpa_s,
        }
 
        data->scan_interval = data->short_interval;
+       data->max_short_scans = data->long_interval / data->short_interval + 1;
        if (data->signal_threshold) {
                /* Poll for signal info to set initial scan interval */
                struct wpa_signal_info siginfo;
@@ -222,9 +225,15 @@ static void bgscan_simple_notify_signal_change(void *priv, int above,
                wpa_printf(MSG_DEBUG, "bgscan simple: Start using short "
                           "bgscan interval");
                data->scan_interval = data->short_interval;
-               data->short_scan_count = 0;
                os_get_time(&now);
-               if (now.sec > data->last_bgscan.sec + 1)
+               if (now.sec > data->last_bgscan.sec + 1 &&
+                   data->short_scan_count <= data->max_short_scans)
+                       /*
+                        * If we haven't just previously (<1 second ago)
+                        * performed a scan, and we haven't depleted our
+                        * budget for short-scans, perform a scan
+                        * immediately.
+                        */
                        scan = 1;
                else if (data->last_bgscan.sec + data->long_interval >
                         now.sec + data->scan_interval) {