iwlwifi: use minimal time for radio reset scan

The effect of using a short single-channel scan
to reset the radio is that scanning a channel
that isn't in use needs to re-tune the radio.
This means that the dwell time is irrelevant,
so use a shorter time.

While at it, clean up the code for this a bit.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 19 insertions, 22 deletions

diff --git a/drivers/net/wireless/iwlwifi/dvm/scan.c b/drivers/net/wireless/iwlwifi/dvm/scan.c
index 2f271c96ed39..f5b1452a60b3 100644
--- a/drivers/net/wireless/iwlwifi/dvm/scan.c
+++ b/drivers/net/wireless/iwlwifi/dvm/scan.c
@@ -51,6 +51,9 @@
 #define IWL_CHANNEL_TUNE_TIME       5
 #define MAX_SCAN_CHANNEL            50
 
+/* For reset radio, need minimal dwell time only */
+#define IWL_RADIO_RESET_DWELL_TIME      5
+
 static int iwl_send_scan_abort(struct iwl_priv *priv)
 {
         int ret;
@@ -469,45 +472,39 @@ static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
         return 0;
 }
 
-static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
-                                           struct ieee80211_vif *vif,
-                                           enum ieee80211_band band,
-                                           struct iwl_scan_channel *scan_ch)
+static int iwl_get_channel_for_reset_scan(struct iwl_priv *priv,
+                                          struct ieee80211_vif *vif,
+                                          enum ieee80211_band band,
+                                          struct iwl_scan_channel *scan_ch)
 {
         const struct ieee80211_supported_band *sband;
-        u16 passive_dwell = 0;
-        u16 active_dwell = 0;
-        int added = 0;
-        u16 channel = 0;
+        u16 channel;
 
         sband = iwl_get_hw_mode(priv, band);
         if (!sband) {
                 IWL_ERR(priv, "invalid band\n");
-                return added;
+                return 0;
         }
 
-        active_dwell = iwl_get_active_dwell_time(priv, band, 0);
-        passive_dwell = iwl_get_passive_dwell_time(priv, band);
-
-        if (passive_dwell <= active_dwell)
-                passive_dwell = active_dwell + 1;
-
         channel = iwl_get_single_channel_number(priv, band);
         if (channel) {
                 scan_ch->channel = cpu_to_le16(channel);
                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
-                scan_ch->active_dwell = cpu_to_le16(active_dwell);
-                scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
+                scan_ch->active_dwell =
+                        cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
+                scan_ch->passive_dwell =
+                        cpu_to_le16(IWL_RADIO_RESET_DWELL_TIME);
                 /* Set txpower levels to defaults */
                 scan_ch->dsp_atten = 110;
                 if (band == IEEE80211_BAND_5GHZ)
                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
                 else
                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
-                added++;
-        } else
-                IWL_ERR(priv, "no valid channel found\n");
-        return added;
+                return 1;
+        }
+
+        IWL_ERR(priv, "no valid channel found\n");
+        return 0;
 }
 
 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
@@ -896,7 +893,7 @@ static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
         switch (priv->scan_type) {
         case IWL_SCAN_RADIO_RESET:
                 scan->channel_count =
-                        iwl_get_single_channel_for_scan(priv, vif, band,
+                        iwl_get_channel_for_reset_scan(priv, vif, band,
                                 (void *)&scan->data[cmd_len]);
                 break;
         case IWL_SCAN_NORMAL: