iwlwifi: mvm: add extended dwell time

When doing active scan on crowded channels we are likely to miss probe
responses due to collisions. To overcome this issue we use an extended
dwell time on channels 1, 6 and 11; this dwell time is set to 100.

In case of fragmented scan extended dwell time is the maximum out of
channel time - 44 msec. Fragmented active scan will be addressed later.

Extended dwell time isn't used in sched scan or p2p find.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/fw-api-scan.h

@@ -285,6 +285,8 @@ struct iwl_scan_channel_opt {
  * @IWL_MVM_LMAC_SCAN_FLAG_FRAGMENTED: all passive scans will be fragmented
  * @IWL_MVM_LMAC_SCAN_FLAGS_RRM_ENABLED: insert WFA vendor-specific TPC report
  *	and DS parameter set IEs into probe requests.
+ * @IWL_MVM_LMAC_SCAN_FLAG_EXTENDED_DWELL: use extended dwell time on channels
+ *	1, 6 and 11.
  * @IWL_MVM_LMAC_SCAN_FLAG_MATCH: Send match found notification on matches
  */
 enum iwl_mvm_lmac_scan_flags {
@@ -295,6 +297,7 @@ enum iwl_mvm_lmac_scan_flags {
 	IWL_MVM_LMAC_SCAN_FLAG_MULTIPLE_SSIDS	= BIT(4),
 	IWL_MVM_LMAC_SCAN_FLAG_FRAGMENTED	= BIT(5),
 	IWL_MVM_LMAC_SCAN_FLAGS_RRM_ENABLED	= BIT(6),
+	IWL_MVM_LMAC_SCAN_FLAG_EXTENDED_DWELL	= BIT(7),
 	IWL_MVM_LMAC_SCAN_FLAG_MATCH		= BIT(9),
 };
 
@@ -322,6 +325,7 @@ enum iwl_scan_priority_ext {
  * @active-dwell: dwell time for active channels
  * @passive-dwell: dwell time for passive channels
  * @fragmented-dwell: dwell time for fragmented passive scan
+ * @extended_dwell: dwell time for channels 1, 6 and 11 (in certain cases)
  * @reserved2: for alignment and future use
  * @rx_chain_selct: PHY_RX_CHAIN_* flags
  * @scan_flags: &enum iwl_mvm_lmac_scan_flags
@@ -346,7 +350,8 @@ struct iwl_scan_req_lmac {
 	u8 active_dwell;
 	u8 passive_dwell;
 	u8 fragmented_dwell;
-	__le16 reserved2;
+	u8 extended_dwell;
+	u8 reserved2;
 	__le16 rx_chain_select;
 	__le32 scan_flags;
 	__le32 max_out_time;
@@ -490,7 +495,7 @@ enum iwl_channel_flags {
  * @dwell_active:		default dwell time for active scan
  * @dwell_passive:		default dwell time for passive scan
  * @dwell_fragmented:		default dwell time for fragmented scan
- * @reserved:			for future use and alignment
+ * @dwell_extended:		default dwell time for channels 1, 6 and 11
  * @mac_addr:			default mac address to be used in probes
  * @bcast_sta_id:		the index of the station in the fw
  * @channel_flags:		default channel flags - enum iwl_channel_flags
@@ -507,7 +512,7 @@ struct iwl_scan_config {
 	u8 dwell_active;
 	u8 dwell_passive;
 	u8 dwell_fragmented;
-	u8 reserved;
+	u8 dwell_extended;
 	u8 mac_addr[ETH_ALEN];
 	u8 bcast_sta_id;
 	u8 channel_flags;
@@ -543,7 +548,8 @@ enum iwl_umac_scan_general_flags {
 	IWL_UMAC_SCAN_GEN_FLAGS_MULTIPLE_SSID	= BIT(6),
 	IWL_UMAC_SCAN_GEN_FLAGS_FRAGMENTED	= BIT(7),
 	IWL_UMAC_SCAN_GEN_FLAGS_RRM_ENABLED	= BIT(8),
-	IWL_UMAC_SCAN_GEN_FLAGS_MATCH		= BIT(9)
+	IWL_UMAC_SCAN_GEN_FLAGS_MATCH		= BIT(9),
+	IWL_UMAC_SCAN_GEN_FLAGS_EXTENDED_DWELL	= BIT(10),
 };
 
 /**
@@ -597,7 +603,7 @@ struct iwl_scan_req_umac_tail {
  * @uid: scan id, &enum iwl_umac_scan_uid_offsets
  * @ooc_priority: out of channel priority - &enum iwl_scan_priority
  * @general_flags: &enum iwl_umac_scan_general_flags
- * @reserved1: for future use and alignment
+ * @extended_dwell: dwell time for channels 1, 6 and 11
  * @active_dwell: dwell time for active scan
  * @passive_dwell: dwell time for passive scan
  * @fragmented_dwell: dwell time for fragmented passive scan
@@ -606,7 +612,7 @@ struct iwl_scan_req_umac_tail {
  * @scan_priority: scan internal prioritization &enum iwl_scan_priority
  * @channel_flags: &enum iwl_scan_channel_flags
  * @n_channels: num of channels in scan request
- * @reserved2: for future use and alignment
+ * @reserved: for future use and alignment
  * @data: &struct iwl_scan_channel_cfg_umac and
  *	&struct iwl_scan_req_umac_tail
  */
@@ -616,7 +622,7 @@ struct iwl_scan_req_umac {
 	__le32 ooc_priority;
 	/* SCAN_GENERAL_PARAMS_API_S_VER_1 */
 	__le32 general_flags;
-	u8 reserved1;
+	u8 extended_dwell;
 	u8 active_dwell;
 	u8 passive_dwell;
 	u8 fragmented_dwell;
@@ -626,7 +632,7 @@ struct iwl_scan_req_umac {
 	/* SCAN_CHANNEL_PARAMS_API_S_VER_1 */
 	u8 channel_flags;
 	u8 n_channels;
-	__le16 reserved2;
+	__le16 reserved;
 	u8 data[];
 } __packed; /* SCAN_REQUEST_CMD_UMAC_API_S_VER_1 */
 

drivers/net/wireless/intel/iwlwifi/mvm/scan.c

@@ -82,6 +82,7 @@ struct iwl_mvm_scan_timing_params {
 	u32 dwell_active;
 	u32 dwell_passive;
 	u32 dwell_fragmented;
+	u32 dwell_extended;
 	u32 suspend_time;
 	u32 max_out_time;
 };
@@ -91,6 +92,7 @@ static struct iwl_mvm_scan_timing_params scan_timing[] = {
 		.dwell_active = 10,
 		.dwell_passive = 110,
 		.dwell_fragmented = 44,
+		.dwell_extended = 100,
 		.suspend_time = 0,
 		.max_out_time = 0,
 	},
@@ -98,6 +100,7 @@ static struct iwl_mvm_scan_timing_params scan_timing[] = {
 		.dwell_active = 10,
 		.dwell_passive = 110,
 		.dwell_fragmented = 44,
+		.dwell_extended = 100,
 		.suspend_time = 30,
 		.max_out_time = 120,
 	},
@@ -105,6 +108,7 @@ static struct iwl_mvm_scan_timing_params scan_timing[] = {
 		.dwell_active = 10,
 		.dwell_passive = 110,
 		.dwell_fragmented = 44,
+		.dwell_extended = 100,
 		.suspend_time = 120,
 		.max_out_time = 120,
 	},
@@ -112,6 +116,7 @@ static struct iwl_mvm_scan_timing_params scan_timing[] = {
 		.dwell_active = 10,
 		.dwell_passive = 110,
 		.dwell_fragmented = 44,
+		.dwell_extended = 44,
 		.suspend_time = 95,
 		.max_out_time = 44,
 	},
@@ -716,6 +721,7 @@ static void iwl_mvm_scan_lmac_dwell(struct iwl_mvm *mvm,
 	cmd->active_dwell = scan_timing[params->type].dwell_active;
 	cmd->passive_dwell = scan_timing[params->type].dwell_passive;
 	cmd->fragmented_dwell = scan_timing[params->type].dwell_fragmented;
+	cmd->extended_dwell = scan_timing[params->type].dwell_extended;
 	cmd->max_out_time = cpu_to_le32(scan_timing[params->type].max_out_time);
 	cmd->suspend_time = cpu_to_le32(scan_timing[params->type].suspend_time);
 	cmd->scan_prio = iwl_mvm_scan_priority(mvm, IWL_SCAN_PRIORITY_EXT_6);
@@ -749,8 +755,15 @@ static inline bool iwl_mvm_scan_use_ebs(struct iwl_mvm *mvm,
 		vif->type != NL80211_IFTYPE_P2P_DEVICE);
 }
 
+static inline bool iwl_mvm_is_regular_scan(struct iwl_mvm_scan_params *params)
+{
+	return params->n_scan_plans == 1 &&
+		params->scan_plans[0].iterations == 1;
+}
+
 static int iwl_mvm_scan_lmac_flags(struct iwl_mvm *mvm,
-				   struct iwl_mvm_scan_params *params)
+				   struct iwl_mvm_scan_params *params,
+				   struct ieee80211_vif *vif)
 {
 	int flags = 0;
 
@@ -776,6 +789,10 @@ static int iwl_mvm_scan_lmac_flags(struct iwl_mvm *mvm,
 		flags |= IWL_MVM_LMAC_SCAN_FLAG_ITER_COMPLETE;
 #endif
 
+	if (iwl_mvm_is_regular_scan(params) &&
+	    vif->type != NL80211_IFTYPE_P2P_DEVICE)
+		flags |= IWL_MVM_LMAC_SCAN_FLAG_EXTENDED_DWELL;
+
 	return flags;
 }
 
@@ -804,7 +821,8 @@ static int iwl_mvm_scan_lmac(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 
 	cmd->delay = cpu_to_le32(params->delay);
 
-	cmd->scan_flags = cpu_to_le32(iwl_mvm_scan_lmac_flags(mvm, params));
+	cmd->scan_flags = cpu_to_le32(iwl_mvm_scan_lmac_flags(mvm, params,
+							      vif));
 
 	cmd->flags = iwl_mvm_scan_rxon_flags(params->channels[0]->band);
 	cmd->filter_flags = cpu_to_le32(MAC_FILTER_ACCEPT_GRP |
@@ -942,6 +960,7 @@ int iwl_mvm_config_scan(struct iwl_mvm *mvm)
 	scan_config->dwell_active = scan_timing[type].dwell_active;
 	scan_config->dwell_passive = scan_timing[type].dwell_passive;
 	scan_config->dwell_fragmented = scan_timing[type].dwell_fragmented;
+	scan_config->dwell_extended = scan_timing[type].dwell_extended;
 
 	memcpy(&scan_config->mac_addr, &mvm->addresses[0].addr, ETH_ALEN);
 
@@ -983,16 +1002,11 @@ static int iwl_mvm_scan_uid_by_status(struct iwl_mvm *mvm, int status)
 	return -ENOENT;
 }
 
-static inline bool iwl_mvm_is_regular_scan(struct iwl_mvm_scan_params *params)
-{
-	return params->n_scan_plans == 1 &&
-		params->scan_plans[0].iterations == 1;
-}
-
 static void iwl_mvm_scan_umac_dwell(struct iwl_mvm *mvm,
 				    struct iwl_scan_req_umac *cmd,
 				    struct iwl_mvm_scan_params *params)
 {
+	cmd->extended_dwell = scan_timing[params->type].dwell_extended;
 	cmd->active_dwell = scan_timing[params->type].dwell_active;
 	cmd->passive_dwell = scan_timing[params->type].dwell_passive;
 	cmd->fragmented_dwell = scan_timing[params->type].dwell_fragmented;
@@ -1027,7 +1041,8 @@ iwl_mvm_umac_scan_cfg_channels(struct iwl_mvm *mvm,
 }
 
 static u32 iwl_mvm_scan_umac_flags(struct iwl_mvm *mvm,
-				   struct iwl_mvm_scan_params *params)
+				   struct iwl_mvm_scan_params *params,
+				   struct ieee80211_vif *vif)
 {
 	int flags = 0;
 
@@ -1055,6 +1070,11 @@ static u32 iwl_mvm_scan_umac_flags(struct iwl_mvm *mvm,
 	if (mvm->scan_iter_notif_enabled)
 		flags |= IWL_UMAC_SCAN_GEN_FLAGS_ITER_COMPLETE;
 #endif
+
+	if (iwl_mvm_is_regular_scan(params) &&
+	    vif->type != NL80211_IFTYPE_P2P_DEVICE)
+		flags |= IWL_UMAC_SCAN_GEN_FLAGS_EXTENDED_DWELL;
+
 	return flags;
 }
 
@@ -1085,7 +1105,8 @@ static int iwl_mvm_scan_umac(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 	mvm->scan_uid_status[uid] = type;
 
 	cmd->uid = cpu_to_le32(uid);
-	cmd->general_flags = cpu_to_le32(iwl_mvm_scan_umac_flags(mvm, params));
+	cmd->general_flags = cpu_to_le32(iwl_mvm_scan_umac_flags(mvm, params,
+								 vif));
 
 	if (type == IWL_MVM_SCAN_SCHED)
 		cmd->flags = cpu_to_le32(IWL_UMAC_SCAN_FLAG_PREEMPTIVE);