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>

diff --git a/drivers/net/wireless/iwlwifi/dvm/scan.c b/drivers/net/wireless/iwlwifi/dvm/scan.c
index 2f271c9..f5b1452 100644 (file)
--- 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: