wl1271: Optimize scan duration

Currently then dwell times for each channel in scans is set to an overly
long value, and excessive number of probe-requests are transmitted on each
channel (for active scans.)

Based on testing, comparable results can be received with smaller dwell-time,
and, with fever probe-requests - in fact, reducing the number of probe-requests
to 2 seems to increase the number of found results.

Configure more optimal values for per channel dwell times. Comparison for the
different scan configurations (in my current office environment):

dwell-time 60000   3x probe-req == ~60 results
           40000   3x probe-req == ~50 results
           30000   3x probe-req == ~40 results

dwell-time 60000   2x probe-req == ~70 results
           40000   2x probe-req == ~60 results
           30000   2x probe-req == ~58 results

The above are results for a cumulative 3 scan run. For individual scans, the
number of results drop slightly more.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>

4 files changed, 60 insertions, 9 deletions

diff --git a/drivers/net/wireless/wl12xx/wl1271_conf.h b/drivers/net/wireless/wl12xx/wl1271_conf.h
index feb493ebe5bd..ab716f517553 100644
--- a/drivers/net/wireless/wl12xx/wl1271_conf.h
+++ b/drivers/net/wireless/wl12xx/wl1271_conf.h
@@ -1016,6 +1016,44 @@ struct conf_roam_trigger_settings {
         u8 avg_weight_snr_data;
 };
 
+struct conf_scan_settings {
+        /*
+         * The minimum time to wait on each channel for active scans
+         *
+         * Range: 0 - 65536 tu
+         */
+        u16 min_dwell_time_active;
+
+        /*
+         * The maximum time to wait on each channel for active scans
+         *
+         * Range: 0 - 65536 tu
+         */
+        u16 max_dwell_time_active;
+
+        /*
+         * The maximum time to wait on each channel for passive scans
+         *
+         * Range: 0 - 65536 tu
+         */
+        u16 min_dwell_time_passive;
+
+        /*
+         * The maximum time to wait on each channel for passive scans
+         *
+         * Range: 0 - 65536 tu
+         */
+        u16 max_dwell_time_passive;
+
+        /*
+         * Number of probe requests to transmit on each active scan channel
+         *
+         * Range: u8
+         */
+        u16 num_probe_reqs;
+
+};
+
 struct conf_drv_settings {
         struct conf_sg_settings sg;
         struct conf_rx_settings rx;
@@ -1024,6 +1062,7 @@ struct conf_drv_settings {
         struct conf_itrim_settings itrim;
         struct conf_pm_config_settings pm_config;
         struct conf_roam_trigger_settings roam_trigger;
+        struct conf_scan_settings scan;
 };
 
 #endif
diff --git a/drivers/net/wireless/wl12xx/wl1271_main.c b/drivers/net/wireless/wl12xx/wl1271_main.c
index c13175892960..b2f2d457f28c 100644
--- a/drivers/net/wireless/wl12xx/wl1271_main.c
+++ b/drivers/net/wireless/wl12xx/wl1271_main.c
@@ -232,7 +232,14 @@ static struct conf_drv_settings default_conf = {
                 .avg_weight_rssi_data         = 10,
                 .avg_weight_snr_beacon        = 20,
                 .avg_weight_snr_data          = 10
-        }
+        },
+        .scan = {
+                .min_dwell_time_active        = 7500,
+                .max_dwell_time_active        = 30000,
+                .min_dwell_time_passive       = 30000,
+                .max_dwell_time_passive       = 60000,
+                .num_probe_reqs               = 2,
+        },
 };
 
 static void __wl1271_op_remove_interface(struct wl1271 *wl);
diff --git a/drivers/net/wireless/wl12xx/wl1271_scan.c b/drivers/net/wireless/wl12xx/wl1271_scan.c
index 37f9ccbe738f..5c76b79a96bf 100644
--- a/drivers/net/wireless/wl12xx/wl1271_scan.c
+++ b/drivers/net/wireless/wl12xx/wl1271_scan.c
@@ -64,6 +64,7 @@ static int wl1271_get_scan_channels(struct wl1271 *wl,
                                     struct basic_scan_channel_params *channels,
                                     enum ieee80211_band band, bool passive)
 {
+        struct conf_scan_settings *c = &wl->conf.scan;
         int i, j;
         u32 flags;
 
@@ -91,10 +92,17 @@ static int wl1271_get_scan_channels(struct wl1271 *wl,
                         wl1271_debug(DEBUG_SCAN, "beacon_found %d",
                                      req->channels[i]->beacon_found);
 
-                        channels[j].min_duration =
-                                cpu_to_le32(WL1271_SCAN_CHAN_MIN_DURATION);
-                        channels[j].max_duration =
-                                cpu_to_le32(WL1271_SCAN_CHAN_MAX_DURATION);
+                        if (!passive) {
+                                channels[j].min_duration =
+                                        cpu_to_le32(c->min_dwell_time_active);
+                                channels[j].max_duration =
+                                        cpu_to_le32(c->max_dwell_time_active);
+                        } else {
+                                channels[j].min_duration =
+                                        cpu_to_le32(c->min_dwell_time_passive);
+                                channels[j].max_duration =
+                                        cpu_to_le32(c->max_dwell_time_passive);
+                        }
                         channels[j].early_termination = 0;
                         channels[j].tx_power_att = req->channels[i]->max_power;
                         channels[j].channel = req->channels[i]->hw_value;
@@ -151,7 +159,7 @@ static int wl1271_scan_send(struct wl1271 *wl, enum ieee80211_band band,
         cmd->params.rx_filter_options =
                 cpu_to_le32(CFG_RX_PRSP_EN | CFG_RX_MGMT_EN | CFG_RX_BCN_EN);
 
-        cmd->params.n_probe_reqs = WL1271_SCAN_PROBE_REQS;
+        cmd->params.n_probe_reqs = wl->conf.scan.num_probe_reqs;
         cmd->params.tx_rate = cpu_to_le32(basic_rate);
         cmd->params.tid_trigger = 0;
         cmd->params.scan_tag = WL1271_SCAN_DEFAULT_TAG;
diff --git a/drivers/net/wireless/wl12xx/wl1271_scan.h b/drivers/net/wireless/wl12xx/wl1271_scan.h
index bb7af2a102fa..6d57127b5e6b 100644
--- a/drivers/net/wireless/wl12xx/wl1271_scan.h
+++ b/drivers/net/wireless/wl12xx/wl1271_scan.h
@@ -40,11 +40,8 @@ void wl1271_scan_complete_work(struct work_struct *work);
 #define WL1271_SCAN_OPT_ACTIVE         0
 #define WL1271_SCAN_OPT_PASSIVE        1
 #define WL1271_SCAN_OPT_PRIORITY_HIGH  4
-#define WL1271_SCAN_CHAN_MIN_DURATION  30000  /* TU */
-#define WL1271_SCAN_CHAN_MAX_DURATION  60000  /* TU */
 #define WL1271_SCAN_BAND_2_4_GHZ 0
 #define WL1271_SCAN_BAND_5_GHZ 1
-#define WL1271_SCAN_PROBE_REQS 3
 
 #define WL1271_SCAN_TIMEOUT    10000 /* msec */