iwlwifi: automatically adjust sleep level

Depending on required latency requested by pm_qos (via mac80211)
we can automatically adjust the sleep state. Also, mac80211 has
a user-visible dynamic sleep feature where we are supposed to
stay awake after sending/receiving frames to better receive
response frames to our packets, this can be integrated into the
sleep command.

Currently, and this patch doesn't change that yet, we default
to using sleep level 1 if PS is enabled. With a module parameter
to iwlcore, automatic adjustment to changing network latency
requirements can be enabled -- this isn't yet the default due
to requiring more testing.

The goal is to enable automatic adjustment and then go into the
deepest possible sleep state possible depending on the networking
latency requirements.

This patch does, however, enable IEEE80211_HW_SUPPORTS_DYNAMIC_PS
to avoid the double-timer (one in software and one in the device)
when transmitting -- the exact timeout may be ignored but that is
not of big concern.

Note also that we keep the hard-coded power indices around for
thermal throttling -- the specification of that calls for using
the specified power levels. Those can also be selected in debugfs
to allow easier testing of such parameters.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 147 insertions, 170 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-power.c b/drivers/net/wireless/iwlwifi/iwl-power.c
index 27ad59d8643..0b16841f45f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-power.c
+++ b/drivers/net/wireless/iwlwifi/iwl-power.c
@@ -42,20 +42,35 @@
 #include "iwl-power.h"
 
 /*
- * Setting power level allow the card to go to sleep when not busy.
+ * Setting power level allows the card to go to sleep when not busy.
  *
- * The power level is set to INDEX_1 (the least deep state) by
- * default, and will, in the future, be the deepest state unless
- * otherwise required by pm_qos network latency requirements.
- *
- * Using INDEX_1 without pm_qos is ok because mac80211 will disable
- * PS when even checking every beacon for the TIM bit would exceed
- * the required latency.
+ * We calculate a sleep command based on the required latency, which
+ * we get from mac80211. In order to handle thermal throttling, we can
+ * also use pre-defined power levels.
  */
 
-#define IWL_POWER_RANGE_0_MAX  (2)
-#define IWL_POWER_RANGE_1_MAX  (10)
+/*
+ * For now, keep using power level 1 instead of automatically
+ * adjusting ...
+ */
+bool no_sleep_autoadjust = true;
+module_param(no_sleep_autoadjust, bool, S_IRUGO);
+MODULE_PARM_DESC(no_sleep_autoadjust,
+		 "don't automatically adjust sleep level "
+		 "according to maximum network latency");
 
+/*
+ * This defines the old power levels. They are still used by default
+ * (level 1) and for thermal throttle (levels 3 through 5)
+ */
+
+struct iwl_power_vec_entry {
+	struct iwl_powertable_cmd cmd;
+	u8 no_dtim;
+};
+
+#define IWL_DTIM_RANGE_0_MAX	2
+#define IWL_DTIM_RANGE_1_MAX	10
 
 #define NOSLP cpu_to_le16(0), 0, 0
 #define SLP IWL_POWER_DRIVER_ALLOW_SLEEP_MSK, 0, 0
@@ -67,9 +82,8 @@
 				     cpu_to_le32(X3), \
 				     cpu_to_le32(X4)}
 /* default power management (not Tx power) table values */
-/* for DTIM period 0 through IWL_POWER_RANGE_0_MAX */
+/* for DTIM period 0 through IWL_DTIM_RANGE_0_MAX */
 static const struct iwl_power_vec_entry range_0[IWL_POWER_NUM] = {
-	{{NOSLP, SLP_TOUT(0), SLP_TOUT(0), SLP_VEC(0, 0, 0, 0, 0)}, 0},
 	{{SLP, SLP_TOUT(200), SLP_TOUT(500), SLP_VEC(1, 2, 2, 2, 0xFF)}, 0},
 	{{SLP, SLP_TOUT(200), SLP_TOUT(300), SLP_VEC(1, 2, 2, 2, 0xFF)}, 0},
 	{{SLP, SLP_TOUT(50), SLP_TOUT(100), SLP_VEC(2, 2, 2, 2, 0xFF)}, 0},
@@ -78,9 +92,8 @@ static const struct iwl_power_vec_entry range_0[IWL_POWER_NUM] = {
 };
 
 
-/* for DTIM period IWL_POWER_RANGE_0_MAX + 1 through IWL_POWER_RANGE_1_MAX */
+/* for DTIM period IWL_DTIM_RANGE_0_MAX + 1 through IWL_DTIM_RANGE_1_MAX */
 static const struct iwl_power_vec_entry range_1[IWL_POWER_NUM] = {
-	{{NOSLP, SLP_TOUT(0), SLP_TOUT(0), SLP_VEC(0, 0, 0, 0, 0)}, 0},
 	{{SLP, SLP_TOUT(200), SLP_TOUT(500), SLP_VEC(1, 2, 3, 4, 4)}, 0},
 	{{SLP, SLP_TOUT(200), SLP_TOUT(300), SLP_VEC(1, 2, 3, 4, 7)}, 0},
 	{{SLP, SLP_TOUT(50), SLP_TOUT(100), SLP_VEC(2, 4, 6, 7, 9)}, 0},
@@ -88,9 +101,8 @@ static const struct iwl_power_vec_entry range_1[IWL_POWER_NUM] = {
 	{{SLP, SLP_TOUT(25), SLP_TOUT(25), SLP_VEC(2, 4, 7, 10, 10)}, 2}
 };
 
-/* for DTIM period > IWL_POWER_RANGE_1_MAX */
+/* for DTIM period > IWL_DTIM_RANGE_1_MAX */
 static const struct iwl_power_vec_entry range_2[IWL_POWER_NUM] = {
-	{{NOSLP, SLP_TOUT(0), SLP_TOUT(0), SLP_VEC(0, 0, 0, 0, 0)}, 0},
 	{{SLP, SLP_TOUT(200), SLP_TOUT(500), SLP_VEC(1, 2, 3, 4, 0xFF)}, 0},
 	{{SLP, SLP_TOUT(200), SLP_TOUT(300), SLP_VEC(2, 4, 6, 7, 0xFF)}, 0},
 	{{SLP, SLP_TOUT(50), SLP_TOUT(100), SLP_VEC(2, 7, 9, 9, 0xFF)}, 0},
@@ -98,6 +110,56 @@ static const struct iwl_power_vec_entry range_2[IWL_POWER_NUM] = {
 	{{SLP, SLP_TOUT(25), SLP_TOUT(25), SLP_VEC(4, 7, 10, 10, 0xFF)}, 0}
 };
 
+static void iwl_static_sleep_cmd(struct iwl_priv *priv,
+				 struct iwl_powertable_cmd *cmd,
+				 enum iwl_power_level lvl, int period)
+{
+	const struct iwl_power_vec_entry *table;
+	int max_sleep, i;
+	bool skip;
+
+	table = range_2;
+	if (period < IWL_DTIM_RANGE_1_MAX)
+		table = range_1;
+	if (period < IWL_DTIM_RANGE_0_MAX)
+		table = range_0;
+
+	BUG_ON(lvl < 0 || lvl >= IWL_POWER_NUM);
+
+	*cmd = table[lvl].cmd;
+
+	if (period == 0) {
+		skip = false;
+		period = 1;
+	} else {
+		skip = !!table[lvl].no_dtim;
+	}
+
+	if (skip) {
+		__le32 slp_itrvl = cmd->sleep_interval[IWL_POWER_VEC_SIZE - 1];
+		max_sleep = le32_to_cpu(slp_itrvl);
+		if (max_sleep == 0xFF)
+			max_sleep = period * (skip + 1);
+		else if (max_sleep > period)
+			max_sleep = (le32_to_cpu(slp_itrvl) / period) * period;
+		cmd->flags |= IWL_POWER_SLEEP_OVER_DTIM_MSK;
+	} else {
+		max_sleep = period;
+		cmd->flags &= ~IWL_POWER_SLEEP_OVER_DTIM_MSK;
+	}
+
+	for (i = 0; i < IWL_POWER_VEC_SIZE; i++)
+		if (le32_to_cpu(cmd->sleep_interval[i]) > max_sleep)
+			cmd->sleep_interval[i] = cpu_to_le32(max_sleep);
+
+	if (priv->power_data.pci_pm)
+		cmd->flags |= IWL_POWER_PCI_PM_MSK;
+	else
+		cmd->flags &= ~IWL_POWER_PCI_PM_MSK;
+
+	IWL_DEBUG_POWER(priv, "Sleep command for index %d\n", lvl + 1);
+}
+
 /* default Thermal Throttling transaction table
  * Current state   |         Throttling Down               |  Throttling Up
  *=============================================================================
@@ -138,98 +200,44 @@ static const struct iwl_tt_restriction restriction_range[IWL_TI_STATE_MAX] = {
 	{IWL_ANT_OK_NONE, IWL_ANT_OK_NONE, false }
 };
 
-/* set card power command */
-static int iwl_set_power(struct iwl_priv *priv, void *cmd)
-{
-	return iwl_send_cmd_pdu(priv, POWER_TABLE_CMD,
-				sizeof(struct iwl_powertable_cmd), cmd);
-}
 
-/* initialize to default */
-static void iwl_power_init_handle(struct iwl_priv *priv)
+static void iwl_power_sleep_cam_cmd(struct iwl_priv *priv,
+				    struct iwl_powertable_cmd *cmd)
 {
-	struct iwl_power_mgr *pow_data;
-	int size = sizeof(struct iwl_power_vec_entry) * IWL_POWER_NUM;
-	struct iwl_powertable_cmd *cmd;
-	int i;
-	u16 lctl;
-
-	IWL_DEBUG_POWER(priv, "Initialize power \n");
-
-	pow_data = &priv->power_data;
-
-	memset(pow_data, 0, sizeof(*pow_data));
-
-	memcpy(&pow_data->pwr_range_0[0], &range_0[0], size);
-	memcpy(&pow_data->pwr_range_1[0], &range_1[0], size);
-	memcpy(&pow_data->pwr_range_2[0], &range_2[0], size);
-
-	lctl = iwl_pcie_link_ctl(priv);
+	memset(cmd, 0, sizeof(*cmd));
 
-	IWL_DEBUG_POWER(priv, "adjust power command flags\n");
+	if (priv->power_data.pci_pm)
+		cmd->flags |= IWL_POWER_PCI_PM_MSK;
 
-	for (i = 0; i < IWL_POWER_NUM; i++) {
-		cmd = &pow_data->pwr_range_0[i].cmd;
-
-		if (lctl & PCI_CFG_LINK_CTRL_VAL_L0S_EN)
-			cmd->flags &= ~IWL_POWER_PCI_PM_MSK;
-		else
-			cmd->flags |= IWL_POWER_PCI_PM_MSK;
-	}
+	IWL_DEBUG_POWER(priv, "Sleep command for CAM\n");
 }
 
-/* adjust power command according to DTIM period and power level*/
-static int iwl_update_power_cmd(struct iwl_priv *priv,
-				struct iwl_powertable_cmd *cmd, u16 mode)
+static void iwl_power_fill_sleep_cmd(struct iwl_priv *priv,
+				     struct iwl_powertable_cmd *cmd,
+				     int dynps_ms, int wakeup_period)
 {
-	struct iwl_power_vec_entry *range;
-	struct iwl_power_mgr *pow_data;
 	int i;
-	u32 max_sleep = 0;
-	u8 period;
-	bool skip;
 
-	if (mode > IWL_POWER_INDEX_5) {
-		IWL_DEBUG_POWER(priv, "Error invalid power mode \n");
-		return -EINVAL;
-	}
+	memset(cmd, 0, sizeof(*cmd));
 
-	pow_data = &priv->power_data;
+	cmd->flags = IWL_POWER_DRIVER_ALLOW_SLEEP_MSK |
+		     IWL_POWER_FAST_PD; /* no use seeing frames for others */
 
-	if (pow_data->dtim_period <= IWL_POWER_RANGE_0_MAX)
-		range = &pow_data->pwr_range_0[0];
-	else if (pow_data->dtim_period <= IWL_POWER_RANGE_1_MAX)
-		range = &pow_data->pwr_range_1[0];
-	else
-		range = &pow_data->pwr_range_2[0];
+	if (priv->power_data.pci_pm)
+		cmd->flags |= IWL_POWER_PCI_PM_MSK;
 
-	period = pow_data->dtim_period;
-	memcpy(cmd, &range[mode].cmd, sizeof(struct iwl_powertable_cmd));
-
-	if (period == 0) {
-		period = 1;
-		skip = false;
-	} else {
-		skip = !!range[mode].no_dtim;
-	}
-
-	if (skip) {
-		__le32 slp_itrvl = cmd->sleep_interval[IWL_POWER_VEC_SIZE - 1];
-		max_sleep = le32_to_cpu(slp_itrvl);
-		if (max_sleep == 0xFF)
-			max_sleep = period * (skip + 1);
-		else if (max_sleep >  period)
-			max_sleep = (le32_to_cpu(slp_itrvl) / period) * period;
-		cmd->flags |= IWL_POWER_SLEEP_OVER_DTIM_MSK;
-	} else {
-		max_sleep = period;
-		cmd->flags &= ~IWL_POWER_SLEEP_OVER_DTIM_MSK;
-	}
+	cmd->rx_data_timeout = cpu_to_le32(1000 * dynps_ms);
+	cmd->tx_data_timeout = cpu_to_le32(1000 * dynps_ms);
 
 	for (i = 0; i < IWL_POWER_VEC_SIZE; i++)
-		if (le32_to_cpu(cmd->sleep_interval[i]) > max_sleep)
-			cmd->sleep_interval[i] = cpu_to_le32(max_sleep);
+		cmd->sleep_interval[i] = cpu_to_le32(wakeup_period);
+
+	IWL_DEBUG_POWER(priv, "Automatic sleep command\n");
+}
 
+static int iwl_set_power(struct iwl_priv *priv, struct iwl_powertable_cmd *cmd)
+{
+	IWL_DEBUG_POWER(priv, "Sending power/sleep command\n");
 	IWL_DEBUG_POWER(priv, "Flags value = 0x%08X\n", cmd->flags);
 	IWL_DEBUG_POWER(priv, "Tx timeout = %u\n", le32_to_cpu(cmd->tx_data_timeout));
 	IWL_DEBUG_POWER(priv, "Rx timeout = %u\n", le32_to_cpu(cmd->rx_data_timeout));
@@ -240,50 +248,54 @@ static int iwl_update_power_cmd(struct iwl_priv *priv,
 			le32_to_cpu(cmd->sleep_interval[3]),
 			le32_to_cpu(cmd->sleep_interval[4]));
 
-	return 0;
+	return iwl_send_cmd_pdu(priv, POWER_TABLE_CMD,
+				sizeof(struct iwl_powertable_cmd), cmd);
 }
 
 
-/*
- * compute the final power mode index
- */
 int iwl_power_update_mode(struct iwl_priv *priv, bool force)
 {
-	struct iwl_power_mgr *setting = &(priv->power_data);
 	int ret = 0;
 	struct iwl_tt_mgmt *tt = &priv->thermal_throttle;
-	u16 uninitialized_var(final_mode);
+	bool enabled = (priv->iw_mode == NL80211_IFTYPE_STATION) &&
+			(priv->hw->conf.flags & IEEE80211_CONF_PS);
 	bool update_chains;
+	struct iwl_powertable_cmd cmd;
+	int dtimper;
 
 	/* Don't update the RX chain when chain noise calibration is running */
 	update_chains = priv->chain_noise_data.state == IWL_CHAIN_NOISE_DONE ||
 			priv->chain_noise_data.state == IWL_CHAIN_NOISE_ALIVE;
 
-	final_mode = priv->power_data.user_power_setting;
-
-	if (setting->power_disabled)
-		final_mode = IWL_POWER_MODE_CAM;
+	if (priv->vif)
+		dtimper = priv->vif->bss_conf.dtim_period;
+	else
+		dtimper = 1;
+
+	/* TT power setting overwrites everything */
+	if (tt->state >= IWL_TI_1)
+		iwl_static_sleep_cmd(priv, &cmd, tt->tt_power_mode, dtimper);
+	else if (!enabled)
+		iwl_power_sleep_cam_cmd(priv, &cmd);
+	else if (priv->power_data.debug_sleep_level_override >= 0)
+		iwl_static_sleep_cmd(priv, &cmd,
+				     priv->power_data.debug_sleep_level_override,
+				     dtimper);
+	else if (no_sleep_autoadjust)
+		iwl_static_sleep_cmd(priv, &cmd, IWL_POWER_INDEX_1, dtimper);
+	else
+		iwl_power_fill_sleep_cmd(priv, &cmd,
+					 priv->hw->conf.dynamic_ps_timeout,
+					 priv->hw->conf.max_sleep_period);
 
-	if (tt->state >= IWL_TI_1) {
-		/* TT power setting overwrite user & system power setting */
-		final_mode = tt->tt_power_mode;
-	}
 	if (iwl_is_ready_rf(priv) &&
-	    ((setting->power_mode != final_mode) || force)) {
-		struct iwl_powertable_cmd cmd;
-
-		if (final_mode != IWL_POWER_MODE_CAM)
+	    (memcmp(&priv->power_data.sleep_cmd, &cmd, sizeof(cmd)) || force)) {
+		if (cmd.flags & IWL_POWER_DRIVER_ALLOW_SLEEP_MSK)
 			set_bit(STATUS_POWER_PMI, &priv->status);
 
-		iwl_update_power_cmd(priv, &cmd, final_mode);
-		cmd.keep_alive_beacons = 0;
-
-		if (final_mode == IWL_POWER_INDEX_5)
-			cmd.flags |= IWL_POWER_FAST_PD;
-
 		ret = iwl_set_power(priv, &cmd);
 		if (!ret) {
-			if (final_mode == IWL_POWER_MODE_CAM)
+			if (!(cmd.flags & IWL_POWER_DRIVER_ALLOW_SLEEP_MSK))
 				clear_bit(STATUS_POWER_PMI, &priv->status);
 
 			if (priv->cfg->ops->lib->update_chain_flags &&
@@ -294,7 +306,7 @@ int iwl_power_update_mode(struct iwl_priv *priv, bool force)
 					"Cannot update the power, chain noise "
 					"calibration running: %d\n",
 					priv->chain_noise_data.state);
-			setting->power_mode = final_mode;
+			memcpy(&priv->power_data.sleep_cmd, &cmd, sizeof(cmd));
 		} else
 			IWL_ERR(priv, "set power fail, ret = %d", ret);
 	}
@@ -303,18 +315,6 @@ int iwl_power_update_mode(struct iwl_priv *priv, bool force)
 }
 EXPORT_SYMBOL(iwl_power_update_mode);
 
-/* set user_power_setting */
-int iwl_power_set_user_mode(struct iwl_priv *priv, u16 mode)
-{
-	if (mode >= IWL_POWER_NUM)
-		return -EINVAL;
-
-	priv->power_data.user_power_setting = mode;
-
-	return iwl_power_update_mode(priv, 0);
-}
-EXPORT_SYMBOL(iwl_power_set_user_mode);
-
 bool iwl_ht_enabled(struct iwl_priv *priv)
 {
 	struct iwl_tt_mgmt *tt = &priv->thermal_throttle;
@@ -349,7 +349,6 @@ enum iwl_antenna_ok iwl_rx_ant_restriction(struct iwl_priv *priv)
 	restriction = tt->restriction + tt->state;
 	return restriction->rx_stream;
 }
-EXPORT_SYMBOL(iwl_rx_ant_restriction);
 
 #define CT_KILL_EXIT_DURATION (5)	/* 5 seconds duration */
 
@@ -429,7 +428,6 @@ static void iwl_legacy_tt_handler(struct iwl_priv *priv, s32 temp)
 {
 	struct iwl_tt_mgmt *tt = &priv->thermal_throttle;
 	enum iwl_tt_state old_state;
-	struct iwl_power_mgr *setting = &priv->power_data;
 
 #ifdef CONFIG_IWLWIFI_DEBUG
 	if ((tt->tt_previous_temp) &&
@@ -456,24 +454,13 @@ static void iwl_legacy_tt_handler(struct iwl_priv *priv, s32 temp)
 	tt->tt_previous_temp = temp;
 #endif
 	if (tt->state != old_state) {
-		if (old_state == IWL_TI_0) {
-			tt->sys_power_mode = setting->power_mode;
-			IWL_DEBUG_POWER(priv, "current power mode: %u\n",
-				setting->power_mode);
-		}
 		switch (tt->state) {
 		case IWL_TI_0:
-			/* when system ready to go back to IWL_TI_0 state
-			 * using system power mode instead of TT power mode
-			 * revert back to the orginal power mode which was saved
-			 * before enter Thermal Throttling state
-			 * update priv->power_data.user_power_setting to the
-			 * required power mode to make sure
-			 * iwl_power_update_mode() will update power correctly.
+			/*
+			 * When the system is ready to go back to IWL_TI_0
+			 * we only have to call iwl_power_update_mode() to
+			 * do so.
 			 */
-			priv->power_data.user_power_setting =
-				tt->sys_power_mode;
-			tt->tt_power_mode = tt->sys_power_mode;
 			break;
 		case IWL_TI_1:
 			tt->tt_power_mode = IWL_POWER_INDEX_3;
@@ -576,13 +563,8 @@ static void iwl_advance_tt_handler(struct iwl_priv *priv, s32 temp)
 	}
 	if (changed) {
 		struct iwl_rxon_cmd *rxon = &priv->staging_rxon;
-		struct iwl_power_mgr *setting = &priv->power_data;
 
 		if (tt->state >= IWL_TI_1) {
-			/* if switching from IWL_TI_0 to other TT state
-			 * save previous power setting in tt->sys_power_mode */
-			if (old_state == IWL_TI_0)
-				tt->sys_power_mode = setting->power_mode;
 			/* force PI = IWL_POWER_INDEX_5 in the case of TI > 0 */
 			tt->tt_power_mode = IWL_POWER_INDEX_5;
 			if (!iwl_ht_enabled(priv))
@@ -599,17 +581,11 @@ static void iwl_advance_tt_handler(struct iwl_priv *priv, s32 temp)
 			}
 
 		} else {
-			/* restore system power setting */
-			/* the previous power mode was saved in
-			 * tt->sys_power_mode when system move into
-			 * Thermal Throttling state
-			 * set power_data.user_power_setting to the previous
-			 * system power mode to make sure power will get
-			 * updated correctly
+			/*
+			 * restore system power setting -- it will be
+			 * recalculated automatically.
 			 */
-			priv->power_data.user_power_setting =
-				tt->sys_power_mode;
-			tt->tt_power_mode = tt->sys_power_mode;
+
 			/* check HT capability and set
 			 * according to the system HT capability
 			 * in case get disabled before */
@@ -761,7 +737,6 @@ EXPORT_SYMBOL(iwl_tt_handler);
 void iwl_tt_initialize(struct iwl_priv *priv)
 {
 	struct iwl_tt_mgmt *tt = &priv->thermal_throttle;
-	struct iwl_power_mgr *setting = &priv->power_data;
 	int size = sizeof(struct iwl_tt_trans) * (IWL_TI_STATE_MAX - 1);
 	struct iwl_tt_trans *transaction;
 
@@ -770,8 +745,6 @@ void iwl_tt_initialize(struct iwl_priv *priv)
 	memset(tt, 0, sizeof(struct iwl_tt_mgmt));
 
 	tt->state = IWL_TI_0;
-	tt->sys_power_mode = setting->power_mode;
-	tt->tt_power_mode = tt->sys_power_mode;
 	init_timer(&priv->thermal_throttle.ct_kill_exit_tm);
 	priv->thermal_throttle.ct_kill_exit_tm.data = (unsigned long)priv;
 	priv->thermal_throttle.ct_kill_exit_tm.function = iwl_tt_check_exit_ct_kill;
@@ -849,9 +822,13 @@ EXPORT_SYMBOL(iwl_tt_exit);
 /* initialize to default */
 void iwl_power_initialize(struct iwl_priv *priv)
 {
-	iwl_power_init_handle(priv);
-	priv->power_data.user_power_setting = IWL_POWER_INDEX_1;
-	/* default to disabled until mac80211 says otherwise */
-	priv->power_data.power_disabled = 1;
+	u16 lctl = iwl_pcie_link_ctl(priv);
+
+	priv->power_data.pci_pm = !(lctl & PCI_CFG_LINK_CTRL_VAL_L0S_EN);
+
+	priv->power_data.debug_sleep_level_override = -1;
+
+	memset(&priv->power_data.sleep_cmd, 0,
+		sizeof(priv->power_data.sleep_cmd));
 }
 EXPORT_SYMBOL(iwl_power_initialize);