iwlwifi: enable active scanning

This patch enables active scan on active channels.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 45 insertions, 41 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
index cf24c2703c9b..efc750d2fc5c 100644
--- a/drivers/net/wireless/iwlwifi/iwl-scan.c
+++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
@@ -38,8 +38,11 @@
 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  * sending probe req.  This should be set long enough to hear probe responses
  * from more than one AP.  */
-#define IWL_ACTIVE_DWELL_TIME_24    (20)       /* all times in msec */
-#define IWL_ACTIVE_DWELL_TIME_52    (10)
+#define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
+#define IWL_ACTIVE_DWELL_TIME_52    (20)
+
+#define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
+#define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
 
 /* For faster active scanning, scan will move to the next channel if fewer than
  * PLCP_QUIET_THRESH packets are heard on this channel within
@@ -48,7 +51,7 @@
  * no other traffic).
  * Disable "quiet" feature by setting PLCP_QUIET_THRESH to 0. */
 #define IWL_PLCP_QUIET_THRESH       __constant_cpu_to_le16(1)  /* packets */
-#define IWL_ACTIVE_QUIET_TIME       __constant_cpu_to_le16(5)  /* msec */
+#define IWL_ACTIVE_QUIET_TIME       __constant_cpu_to_le16(10)  /* msec */
 
 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  * Must be set longer than active dwell time.
@@ -58,10 +61,15 @@
 #define IWL_PASSIVE_DWELL_BASE      (100)
 #define IWL_CHANNEL_TUNE_TIME       5
 
+#define IWL_SCAN_PROBE_MASK(n)  cpu_to_le32((BIT(n) | (BIT(n) - BIT(1))))
+
+
 static int scan_tx_ant[3] = {
         RATE_MCS_ANT_A_MSK, RATE_MCS_ANT_B_MSK, RATE_MCS_ANT_C_MSK
 };
 
+
+
 static int iwl_is_empty_essid(const char *essid, int essid_len)
 {
         /* Single white space is for Linksys APs */
@@ -226,8 +234,9 @@ static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
                        notif->channel,
                        notif->band ? "bg" : "a",
-                       notif->tsf_high,
-                       notif->tsf_low, notif->status, notif->beacon_timer);
+                       le32_to_cpu(notif->tsf_high),
+                       le32_to_cpu(notif->tsf_low),
+                       notif->status, notif->beacon_timer);
 }
 
 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
@@ -332,19 +341,21 @@ void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 
 static inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
-                                                enum ieee80211_band band)
+                                            enum ieee80211_band band,
+                                            u8 n_probes)
 {
         if (band == IEEE80211_BAND_5GHZ)
-                return IWL_ACTIVE_DWELL_TIME_52;
+                return IWL_ACTIVE_DWELL_TIME_52 +
+                        IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
         else
-                return IWL_ACTIVE_DWELL_TIME_24;
+                return IWL_ACTIVE_DWELL_TIME_24 +
+                        IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 }
 
 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
-                                          enum ieee80211_band band)
+                                      enum ieee80211_band band)
 {
-        u16 active = iwl_get_active_dwell_time(priv, band);
-        u16 passive = (band != IEEE80211_BAND_5GHZ) ?
+        u16 passive = (band == IEEE80211_BAND_2GHZ) ?
             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 
@@ -358,15 +369,12 @@ static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
         }
 
-        if (passive <= active)
-                passive = active + 1;
-
         return passive;
 }
 
 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
                                      enum ieee80211_band band,
-                                     u8 is_active, u8 direct_mask,
+                                     u8 is_active, u8 n_probes,
                                      struct iwl_scan_channel *scan_ch)
 {
         const struct ieee80211_channel *channels = NULL;
@@ -383,9 +391,12 @@ static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 
         channels = sband->channels;
 
-        active_dwell = iwl_get_active_dwell_time(priv, band);
+        active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 
+        if (passive_dwell <= active_dwell)
+                passive_dwell = active_dwell + 1;
+
         for (i = 0, added = 0; i < sband->n_channels; i++) {
                 if (channels[i].flags & IEEE80211_CHAN_DISABLED)
                         continue;
@@ -407,8 +418,8 @@ static int iwl_get_channels_for_scan(struct iwl_priv *priv,
                 else
                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 
-                if (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE)
-                        scan_ch->type |= cpu_to_le32(direct_mask << 1);
+                if ((scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) && n_probes)
+                        scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 
                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
@@ -416,18 +427,17 @@ static int iwl_get_channels_for_scan(struct iwl_priv *priv,
                 /* Set txpower levels to defaults */
                 scan_ch->dsp_atten = 110;
 
+                /* NOTE: if we were doing 6Mb OFDM for scans we'd use
+                 * power level:
+                 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
+                 */
                 if (band == IEEE80211_BAND_5GHZ)
                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
-                else {
+                else
                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
-                        /* NOTE: if we were doing 6Mb OFDM for scans we'd use
-                         * power level:
-                         * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
-                         */
-                }
 
-                IWL_DEBUG_SCAN("Scanning %d [%s %d]\n",
-                               channel,
+                IWL_DEBUG_SCAN("Scanning ch=%d prob=0x%X [%s %d]\n",
+                               channel, le32_to_cpu(scan_ch->type),
                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
                                 "ACTIVE" : "PASSIVE",
                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
@@ -676,7 +686,7 @@ static u32 iwl_scan_tx_ant(struct iwl_priv *priv, enum ieee80211_band band)
                         break;
                 }
         }
-
+        IWL_DEBUG_SCAN("select TX ANT = %c\n", 'A' + ind);
         return scan_tx_ant[ind];
 }
 
@@ -696,7 +706,7 @@ static void iwl_bg_request_scan(struct work_struct *data)
         u32 tx_ant;
         u16 cmd_len;
         enum ieee80211_band band;
-        u8 direct_mask;
+        u8 n_probes = 2;
         u8 rx_chain = 0x7; /* bitmap: ABC chains */
 
         conf = ieee80211_get_hw_conf(priv->hw);
@@ -796,17 +806,16 @@ static void iwl_bg_request_scan(struct work_struct *data)
                 scan->direct_scan[0].len = priv->direct_ssid_len;
                 memcpy(scan->direct_scan[0].ssid,
                        priv->direct_ssid, priv->direct_ssid_len);
-                direct_mask = 1;
+                n_probes++;
         } else if (!iwl_is_associated(priv) && priv->essid_len) {
                 IWL_DEBUG_SCAN("Start direct scan for '%s' (not associated)\n",
                                 iwl_escape_essid(priv->essid, priv->essid_len));
                 scan->direct_scan[0].id = WLAN_EID_SSID;
                 scan->direct_scan[0].len = priv->essid_len;
                 memcpy(scan->direct_scan[0].ssid, priv->essid, priv->essid_len);
-                direct_mask = 1;
+                n_probes++;
         } else {
                 IWL_DEBUG_SCAN("Start indirect scan.\n");
-                direct_mask = 0;
         }
 
         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
@@ -863,16 +872,11 @@ static void iwl_bg_request_scan(struct work_struct *data)
         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
                                RXON_FILTER_BCON_AWARE_MSK);
 
-        if (direct_mask)
-                scan->channel_count =
-                        iwl_get_channels_for_scan(priv, band, 1, /* active */
-                                                  direct_mask,
-                                (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
-        else
-                scan->channel_count =
-                        iwl_get_channels_for_scan(priv, band, 0, /* passive */
-                                                  direct_mask,
-                                (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
+        scan->channel_count =
+                iwl_get_channels_for_scan(priv, band, 1, /* active */
+                        n_probes,
+                        (void *)&scan->data[le16_to_cpu(scan->tx_cmd.len)]);
+
         if (scan->channel_count == 0) {
                 IWL_DEBUG_SCAN("channel count %d\n", scan->channel_count);
                 goto done;