iwlwifi: mvm: configure low latency dependent scan parameters

In case of system low latency configure passive scan to be fragmented.
Set the following scan parameters for both immediate and scheduled scan:
 - passive scan fragment duration = 20ms
 - out-of-channel time = 70ms
 - suspend time = 105ms
Restructure channel's active/passive dwell time configuration to better
suit the above change.

The idea is that under low latency traffic passive scan is fragmented,
i.e. that dwell on a particular channel will be fragmented. Each
fragment dwell time is 20ms and fragments period is 105ms. Skipping to
next channel will be delayed by the same period (105ms). So suspend_time
parameter describing both fragments and channels skipping periods is set
to 105ms. This value is chosen so that overall passive scan duration
will not be too long. Max_out_time in this case is set to 70ms, so for
active scanning operating channel will be left for 70ms while for
passive still for 20ms (fragment dwell).

Signed-off-by: Alexander Bondar <alexander.bondar@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/utils.c b/drivers/net/wireless/iwlwifi/mvm/utils.c
index e9de033d6b9e..c28da90cd347 100644
--- a/drivers/net/wireless/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/iwlwifi/mvm/utils.c
@@ -622,3 +622,22 @@ int iwl_mvm_update_low_latency(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 
 	return iwl_mvm_power_update_mac(mvm, vif);
 }
+
+static void iwl_mvm_ll_iter(void *_data, u8 *mac, struct ieee80211_vif *vif)
+{
+	bool *result = _data;
+
+	if (iwl_mvm_vif_low_latency(iwl_mvm_vif_from_mac80211(vif)))
+		*result = true;
+}
+
+bool iwl_mvm_low_latency(struct iwl_mvm *mvm)
+{
+	bool result = false;
+
+	ieee80211_iterate_active_interfaces_atomic(
+			mvm->hw, IEEE80211_IFACE_ITER_NORMAL,
+			iwl_mvm_ll_iter, &result);
+
+	return result;
+}