iwlwifi: Thermal Throttling Management - part 2

Part 2 of Thermal Throttling Management -

Thermal Throttling feature is used to put NIC into low power state when
driver detect the Radio temperature reach pre-defined threshold

Two Thermal Throttling Management Methods; this patch introduce the
Advance Thermal Throttling:
TI-0: system power index, no tx/rx restriction, HT enabled
TI-1: power index 5, 1 spatial stream Tx, multiple spatial stream Rx, HT
enabled
TI-2: power index 5: 1 spatial stream Tx, 1 spatial stream Rx, HT
disabled
TI-CT-KILL: power index 5, no Tx, no Rx, HT disabled

For advance Thermal Throttling, CT_KILL_ENTER threshold and CT_KILL_EXIT
threshold are different; uCode will not stay awake until reach
CT_KILL_EXIT threshold.
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-agn-rs.c

@@ -177,7 +177,7 @@ static void rs_rate_scale_perform(struct iwl_priv *priv,
 				   struct sk_buff *skb,
 				   struct ieee80211_sta *sta,
 				   struct iwl_lq_sta *lq_sta);
-static void rs_fill_link_cmd(const struct iwl_priv *priv,
+static void rs_fill_link_cmd(struct iwl_priv *priv,
 			     struct iwl_lq_sta *lq_sta, u32 rate_n_flags);
 
 
@@ -1398,6 +1398,12 @@ static int rs_move_legacy_other(struct iwl_priv *priv,
 	int ret = 0;
 	u8 update_search_tbl_counter = 0;
 
+	if (!iwl_ht_enabled(priv))
+		/* stay in Legacy */
+		tbl->action = IWL_LEGACY_SWITCH_ANTENNA1;
+	else if (iwl_tx_ant_restriction(priv) == IWL_TX_SINGLE &&
+		   tbl->action > IWL_LEGACY_SWITCH_SISO)
+		tbl->action = IWL_LEGACY_SWITCH_SISO;
 	for (; ;) {
 		lq_sta->action_counter++;
 		switch (tbl->action) {
@@ -1529,6 +1535,11 @@ static int rs_move_siso_to_other(struct iwl_priv *priv,
 	u8 update_search_tbl_counter = 0;
 	int ret;
 
+	if (iwl_tx_ant_restriction(priv) == IWL_TX_SINGLE &&
+	    tbl->action > IWL_SISO_SWITCH_ANTENNA2) {
+		/* stay in SISO */
+		tbl->action = IWL_SISO_SWITCH_ANTENNA1;
+	}
 	for (;;) {
 		lq_sta->action_counter++;
 		switch (tbl->action) {
@@ -1663,6 +1674,12 @@ static int rs_move_mimo2_to_other(struct iwl_priv *priv,
 	u8 update_search_tbl_counter = 0;
 	int ret;
 
+	if ((iwl_tx_ant_restriction(priv) == IWL_TX_SINGLE) &&
+	    (tbl->action < IWL_MIMO2_SWITCH_SISO_A ||
+	     tbl->action > IWL_MIMO2_SWITCH_SISO_C)) {
+		/* switch in SISO */
+		tbl->action = IWL_MIMO2_SWITCH_SISO_A;
+	}
 	for (;;) {
 		lq_sta->action_counter++;
 		switch (tbl->action) {
@@ -1799,6 +1816,12 @@ static int rs_move_mimo3_to_other(struct iwl_priv *priv,
 	int ret;
 	u8 update_search_tbl_counter = 0;
 
+	if ((iwl_tx_ant_restriction(priv) == IWL_TX_SINGLE) &&
+	    (tbl->action < IWL_MIMO3_SWITCH_SISO_A ||
+	     tbl->action > IWL_MIMO3_SWITCH_SISO_C)) {
+		/* switch in SISO */
+		tbl->action = IWL_MIMO3_SWITCH_SISO_A;
+	}
 	for (;;) {
 		lq_sta->action_counter++;
 		switch (tbl->action) {
@@ -2178,8 +2201,8 @@ static void rs_rate_scale_perform(struct iwl_priv *priv,
 			tbl->expected_tpt[index] + 64) / 128));
 
 	/* If we are searching for better modulation mode, check success. */
-	if (lq_sta->search_better_tbl) {
-
+	if (lq_sta->search_better_tbl &&
+	    (iwl_tx_ant_restriction(priv) == IWL_TX_MULTI)) {
 		/* If good success, continue using the "search" mode;
 		 * no need to send new link quality command, since we're
 		 * continuing to use the setup that we've been trying. */
@@ -2307,7 +2330,11 @@ static void rs_rate_scale_perform(struct iwl_priv *priv,
 		    ((sr > IWL_RATE_HIGH_TH) ||
 		     (current_tpt > (100 * tbl->expected_tpt[low]))))
 		scale_action = 0;
-
+	if (!iwl_ht_enabled(priv) && !is_legacy(tbl->lq_type))
+		scale_action = -1;
+	if (iwl_tx_ant_restriction(priv) != IWL_TX_MULTI &&
+		(is_mimo2(tbl->lq_type) || is_mimo3(tbl->lq_type)))
+		scale_action = -1;
 	switch (scale_action) {
 	case -1:
 		/* Decrease starting rate, update uCode's rate table */
@@ -2341,9 +2368,11 @@ lq_update:
 		rate = rs_update_rate_tbl(priv, lq_sta,
 					  tbl, index, is_green);
 
-	/* Should we stay with this modulation mode, or search for a new one? */
+	if (iwl_tx_ant_restriction(priv) == IWL_TX_MULTI) {
+		/* Should we stay with this modulation mode,
+		 * or search for a new one? */
 		rs_stay_in_table(lq_sta);
-
+	}
 	/*
 	 * Search for new modulation mode if we're:
 	 * 1)  Not changing rates right now
@@ -2400,7 +2429,8 @@ lq_update:
 		 * have been tried and compared, stay in this best modulation
 		 * mode for a while before next round of mode comparisons. */
 		if (lq_sta->enable_counter &&
-		    (lq_sta->action_counter >= tbl1->max_search)) {
+		    (lq_sta->action_counter >= tbl1->max_search) &&
+		    iwl_ht_enabled(priv)) {
 			if ((lq_sta->last_tpt > IWL_AGG_TPT_THREHOLD) &&
 			    (lq_sta->tx_agg_tid_en & (1 << tid)) &&
 			    (tid != MAX_TID_COUNT)) {
@@ -2686,7 +2716,7 @@ static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 	rs_initialize_lq(priv, conf, sta, lq_sta);
 }
 
-static void rs_fill_link_cmd(const struct iwl_priv *priv,
+static void rs_fill_link_cmd(struct iwl_priv *priv,
 			     struct iwl_lq_sta *lq_sta, u32 new_rate)
 {
 	struct iwl_scale_tbl_info tbl_type;

drivers/net/wireless/iwlwifi/iwl-power.h

@@ -33,8 +33,18 @@
 
 struct iwl_priv;
 
+#define IWL_ABSOLUTE_ZERO		0
+#define IWL_ABSOLUTE_MAX		0xFFFFFFFF
 #define IWL_TT_INCREASE_MARGIN	5
 
+/* Tx/Rx restrictions */
+#define IWL_TX_MULTI		0x02
+#define IWL_TX_SINGLE		0x01
+#define IWL_TX_NONE		0x00
+#define IWL_RX_MULTI		0x02
+#define IWL_RX_SINGLE		0x01
+#define IWL_RX_NONE		0x00
+
 /* Thermal Throttling State Machine states */
 enum  iwl_tt_state {
 	IWL_TI_0,	/* normal temperature, system power state */
@@ -44,6 +54,35 @@ enum  iwl_tt_state {
 	IWL_TI_STATE_MAX
 };
 
+/**
+ * struct iwl_tt_restriction - Thermal Throttling restriction table used
+ *		by advance thermal throttling management
+ *		based on the current thermal throttling state, determine
+ *		number of tx/rx streams; and the status of HT operation
+ * @tx_stream: number of tx stream allowed
+ * @is_ht: ht enable/disable
+ * @rx_stream: number of rx stream allowed
+ */
+struct iwl_tt_restriction {
+	u8 tx_stream;
+	bool is_ht;
+	u8 rx_stream;
+};
+
+/**
+ * struct iwl_tt_trans - Thermal Throttling transaction table; used by
+ * 		advance thermal throttling algorithm to determine next
+ *		thermal state to go based on the current temperature
+ * @next_state:  next thermal throttling mode
+ * @tt_low: low temperature threshold to change state
+ * @tt_high: high temperature threshold to change state
+ */
+struct iwl_tt_trans {
+	enum iwl_tt_state next_state;
+	u32 tt_low;
+	u32 tt_high;
+};
+
 /**
  * struct iwl_tt_mgnt - Thermal Throttling Management structure
  * @state:          current Thermal Throttling state
@@ -55,6 +94,11 @@ enum  iwl_tt_state {
  * @sys_power_mode: previous system power mode
  *                  before transition into TT state
  * @tt_previous_temperature: last measured temperature
+ * @iwl_tt_restriction: ptr to restriction tbl, used by advance
+ *		    thermal throttling to determine how many tx/rx streams
+ *		    should be used in tt state; and can HT be enabled or not
+ * @iwl_tt_trans: ptr to adv trans table, used by advance thermal throttling
+ *		    state transaction
  */
 struct iwl_tt_mgmt {
 	enum iwl_tt_state state;
@@ -63,6 +107,8 @@ struct iwl_tt_mgmt {
 #ifdef CONFIG_IWLWIFI_DEBUG
 	s32 tt_previous_temp;
 #endif
+	struct iwl_tt_restriction *restriction;
+	struct iwl_tt_trans *transaction;
 };
 
 enum {
@@ -92,6 +138,8 @@ struct iwl_power_mgr {
 	u8 user_power_setting; /* set by user through sysfs */
 	u8 power_disabled; /* set by mac80211's CONF_PS */
 	struct iwl_tt_mgmt tt; /* Thermal Throttling Management */
+	bool adv_tt;		/* false: legacy mode */
+				/* true: advance mode */
 	bool ct_kill_toggle;   /* use to toggle the CSR bit when
 				* checking uCode temperature
 				*/
@@ -100,6 +148,9 @@ struct iwl_power_mgr {
 
 int iwl_power_update_mode(struct iwl_priv *priv, bool force);
 int iwl_power_set_user_mode(struct iwl_priv *priv, u16 mode);
+bool iwl_ht_enabled(struct iwl_priv *priv);
+u8 iwl_tx_ant_restriction(struct iwl_priv *priv);
+u8 iwl_rx_ant_restriction(struct iwl_priv *priv);
 void iwl_tt_enter_ct_kill(struct iwl_priv *priv);
 void iwl_tt_exit_ct_kill(struct iwl_priv *priv);
 void iwl_tt_handler(struct iwl_priv *priv);