openwrt/package/kernel/mac80211/patches/380-0008-ath10k-DFS-Host-Co...

547 lines
17 KiB
Diff

From 6f6eb1bcbeff48c875617b800f00f1c5d1b12290 Mon Sep 17 00:00:00 2001
From: Sriram R <srirrama@codeaurora.org>
Date: Tue, 15 May 2018 14:39:49 +0530
Subject: [PATCH] ath10k: DFS Host Confirmation
In the 10.4-3.6 firmware branch there's a new DFS Host confirmation
feature which is advertised using WMI_SERVICE_HOST_DFS_CHECK_SUPPORT flag.
This new features enables the ath10k host to send information to the
firmware on the specifications of detected radar type. This allows the
firmware to validate if the host's radar pattern detector unit is
operational and check if the radar information shared by host matches
the radar pulses sent as phy error events from firmware. If the check
fails the firmware won't allow use of DFS channels on AP mode when using
FCC regulatory region.
Hence this patch is mandatory when using a firmware from 10.4-3.6 branch.
Else, DFS channels on FCC regions cannot be used.
Supported Chipsets : QCA9984/QCA9888/QCA4019
Firmware Version : 10.4-3.6-00104
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
---
drivers/net/wireless/ath/ath10k/core.h | 21 ++++
drivers/net/wireless/ath/ath10k/mac.c | 12 ++
drivers/net/wireless/ath/ath10k/wmi-ops.h | 32 +++++
drivers/net/wireless/ath/ath10k/wmi.c | 186 ++++++++++++++++++++++++++++--
drivers/net/wireless/ath/ath10k/wmi.h | 32 +++++
5 files changed, 273 insertions(+), 10 deletions(-)
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -171,6 +171,7 @@ struct ath10k_wmi {
struct completion service_ready;
struct completion unified_ready;
struct completion barrier;
+ struct completion radar_confirm;
wait_queue_head_t tx_credits_wq;
DECLARE_BITMAP(svc_map, WMI_SERVICE_MAX);
struct wmi_cmd_map *cmd;
@@ -352,6 +353,21 @@ struct ath10k_dfs_stats {
u32 radar_detected;
};
+enum ath10k_radar_confirmation_state {
+ ATH10K_RADAR_CONFIRMATION_IDLE = 0,
+ ATH10K_RADAR_CONFIRMATION_INPROGRESS,
+ ATH10K_RADAR_CONFIRMATION_STOPPED,
+};
+
+struct ath10k_radar_found_info {
+ u32 pri_min;
+ u32 pri_max;
+ u32 width_min;
+ u32 width_max;
+ u32 sidx_min;
+ u32 sidx_max;
+};
+
#define ATH10K_MAX_NUM_PEER_IDS (1 << 11) /* htt rx_desc limit */
struct ath10k_peer {
@@ -1026,6 +1042,11 @@ struct ath10k {
void *ce_priv;
+ /* protected by data_lock */
+ enum ath10k_radar_confirmation_state radar_conf_state;
+ struct ath10k_radar_found_info last_radar_info;
+ struct work_struct radar_confirmation_work;
+
/* must be last */
u8 drv_priv[0] __aligned(sizeof(void *));
};
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -3216,6 +3216,15 @@ static void ath10k_reg_notifier(struct w
ar->hw->wiphy->bands[NL80211_BAND_5GHZ]);
}
+static void ath10k_stop_radar_confirmation(struct ath10k *ar)
+{
+ spin_lock_bh(&ar->data_lock);
+ ar->radar_conf_state = ATH10K_RADAR_CONFIRMATION_STOPPED;
+ spin_unlock_bh(&ar->data_lock);
+
+ cancel_work_sync(&ar->radar_confirmation_work);
+}
+
/***************/
/* TX handlers */
/***************/
@@ -4315,6 +4324,7 @@ void ath10k_halt(struct ath10k *ar)
ath10k_scan_finish(ar);
ath10k_peer_cleanup_all(ar);
+ ath10k_stop_radar_confirmation(ar);
ath10k_core_stop(ar);
ath10k_hif_power_down(ar);
@@ -4733,6 +4743,8 @@ static int ath10k_start(struct ieee80211
ath10k_spectral_start(ar);
ath10k_thermal_set_throttling(ar);
+ ar->radar_conf_state = ATH10K_RADAR_CONFIRMATION_IDLE;
+
mutex_unlock(&ar->conf_mutex);
return 0;
--- a/drivers/net/wireless/ath/ath10k/wmi-ops.h
+++ b/drivers/net/wireless/ath/ath10k/wmi-ops.h
@@ -53,6 +53,8 @@ struct wmi_ops {
struct wmi_wow_ev_arg *arg);
int (*pull_echo_ev)(struct ath10k *ar, struct sk_buff *skb,
struct wmi_echo_ev_arg *arg);
+ int (*pull_dfs_status_ev)(struct ath10k *ar, struct sk_buff *skb,
+ struct wmi_dfs_status_ev_arg *arg);
enum wmi_txbf_conf (*get_txbf_conf_scheme)(struct ath10k *ar);
struct sk_buff *(*gen_pdev_suspend)(struct ath10k *ar, u32 suspend_opt);
@@ -178,6 +180,9 @@ struct wmi_ops {
const struct wmi_tdls_peer_update_cmd_arg *arg,
const struct wmi_tdls_peer_capab_arg *cap,
const struct wmi_channel_arg *chan);
+ struct sk_buff *(*gen_radar_found)
+ (struct ath10k *ar,
+ const struct ath10k_radar_found_info *arg);
struct sk_buff *(*gen_adaptive_qcs)(struct ath10k *ar, bool enable);
struct sk_buff *(*gen_pdev_get_tpc_config)(struct ath10k *ar,
u32 param);
@@ -365,6 +370,16 @@ ath10k_wmi_pull_echo_ev(struct ath10k *a
return ar->wmi.ops->pull_echo_ev(ar, skb, arg);
}
+static inline int
+ath10k_wmi_pull_dfs_status(struct ath10k *ar, struct sk_buff *skb,
+ struct wmi_dfs_status_ev_arg *arg)
+{
+ if (!ar->wmi.ops->pull_dfs_status_ev)
+ return -EOPNOTSUPP;
+
+ return ar->wmi.ops->pull_dfs_status_ev(ar, skb, arg);
+}
+
static inline enum wmi_txbf_conf
ath10k_wmi_get_txbf_conf_scheme(struct ath10k *ar)
{
@@ -1438,4 +1453,21 @@ ath10k_wmi_pdev_get_tpc_table_cmdid(stru
ar->wmi.cmd->pdev_get_tpc_table_cmdid);
}
+static inline int
+ath10k_wmi_report_radar_found(struct ath10k *ar,
+ const struct ath10k_radar_found_info *arg)
+{
+ struct sk_buff *skb;
+
+ if (!ar->wmi.ops->gen_radar_found)
+ return -EOPNOTSUPP;
+
+ skb = ar->wmi.ops->gen_radar_found(ar, arg);
+ if (IS_ERR(skb))
+ return PTR_ERR(skb);
+
+ return ath10k_wmi_cmd_send(ar, skb,
+ ar->wmi.cmd->radar_found_cmdid);
+}
+
#endif
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -34,6 +34,7 @@
#define ATH10K_WMI_BARRIER_ECHO_ID 0xBA991E9
#define ATH10K_WMI_BARRIER_TIMEOUT_HZ (3 * HZ)
+#define ATH10K_WMI_DFS_CONF_TIMEOUT_HZ (HZ / 6)
/* MAIN WMI cmd track */
static struct wmi_cmd_map wmi_cmd_map = {
@@ -198,6 +199,7 @@ static struct wmi_cmd_map wmi_cmd_map =
.set_cca_params_cmdid = WMI_CMD_UNSUPPORTED,
.pdev_bss_chan_info_request_cmdid = WMI_CMD_UNSUPPORTED,
.pdev_get_tpc_table_cmdid = WMI_CMD_UNSUPPORTED,
+ .radar_found_cmdid = WMI_CMD_UNSUPPORTED,
};
/* 10.X WMI cmd track */
@@ -365,6 +367,7 @@ static struct wmi_cmd_map wmi_10x_cmd_ma
.set_cca_params_cmdid = WMI_CMD_UNSUPPORTED,
.pdev_bss_chan_info_request_cmdid = WMI_CMD_UNSUPPORTED,
.pdev_get_tpc_table_cmdid = WMI_CMD_UNSUPPORTED,
+ .radar_found_cmdid = WMI_CMD_UNSUPPORTED,
};
/* 10.2.4 WMI cmd track */
@@ -532,6 +535,7 @@ static struct wmi_cmd_map wmi_10_2_4_cmd
.pdev_bss_chan_info_request_cmdid =
WMI_10_2_PDEV_BSS_CHAN_INFO_REQUEST_CMDID,
.pdev_get_tpc_table_cmdid = WMI_CMD_UNSUPPORTED,
+ .radar_found_cmdid = WMI_CMD_UNSUPPORTED,
};
/* 10.4 WMI cmd track */
@@ -741,6 +745,7 @@ static struct wmi_cmd_map wmi_10_4_cmd_m
.tdls_set_state_cmdid = WMI_10_4_TDLS_SET_STATE_CMDID,
.tdls_peer_update_cmdid = WMI_10_4_TDLS_PEER_UPDATE_CMDID,
.tdls_set_offchan_mode_cmdid = WMI_10_4_TDLS_SET_OFFCHAN_MODE_CMDID,
+ .radar_found_cmdid = WMI_10_4_RADAR_FOUND_CMDID,
};
/* MAIN WMI VDEV param map */
@@ -1485,6 +1490,7 @@ static struct wmi_cmd_map wmi_10_2_cmd_m
.pdev_get_ani_ofdm_config_cmdid = WMI_CMD_UNSUPPORTED,
.pdev_reserve_ast_entry_cmdid = WMI_CMD_UNSUPPORTED,
.pdev_get_tpc_table_cmdid = WMI_CMD_UNSUPPORTED,
+ .radar_found_cmdid = WMI_CMD_UNSUPPORTED,
};
static struct wmi_pdev_param_map wmi_10_4_pdev_param_map = {
@@ -3638,6 +3644,68 @@ void ath10k_wmi_event_tbttoffset_update(
ath10k_dbg(ar, ATH10K_DBG_WMI, "WMI_TBTTOFFSET_UPDATE_EVENTID\n");
}
+static void ath10k_radar_detected(struct ath10k *ar)
+{
+ ath10k_dbg(ar, ATH10K_DBG_REGULATORY, "dfs radar detected\n");
+ ATH10K_DFS_STAT_INC(ar, radar_detected);
+
+ /* Control radar events reporting in debugfs file
+ * dfs_block_radar_events
+ */
+ if (ar->dfs_block_radar_events)
+ ath10k_info(ar, "DFS Radar detected, but ignored as requested\n");
+ else
+ ieee80211_radar_detected(ar->hw);
+}
+
+static void ath10k_radar_confirmation_work(struct work_struct *work)
+{
+ struct ath10k *ar = container_of(work, struct ath10k,
+ radar_confirmation_work);
+ struct ath10k_radar_found_info radar_info;
+ int ret, time_left;
+
+ reinit_completion(&ar->wmi.radar_confirm);
+
+ spin_lock_bh(&ar->data_lock);
+ memcpy(&radar_info, &ar->last_radar_info, sizeof(radar_info));
+ spin_unlock_bh(&ar->data_lock);
+
+ ret = ath10k_wmi_report_radar_found(ar, &radar_info);
+ if (ret) {
+ ath10k_warn(ar, "failed to send radar found %d\n", ret);
+ goto wait_complete;
+ }
+
+ time_left = wait_for_completion_timeout(&ar->wmi.radar_confirm,
+ ATH10K_WMI_DFS_CONF_TIMEOUT_HZ);
+ if (time_left) {
+ /* DFS Confirmation status event received and
+ * necessary action completed.
+ */
+ goto wait_complete;
+ } else {
+ /* DFS Confirmation event not received from FW.Considering this
+ * as real radar.
+ */
+ ath10k_dbg(ar, ATH10K_DBG_REGULATORY,
+ "dfs confirmation not received from fw, considering as radar\n");
+ goto radar_detected;
+ }
+
+radar_detected:
+ ath10k_radar_detected(ar);
+
+ /* Reset state to allow sending confirmation on consecutive radar
+ * detections, unless radar confirmation is disabled/stopped.
+ */
+wait_complete:
+ spin_lock_bh(&ar->data_lock);
+ if (ar->radar_conf_state != ATH10K_RADAR_CONFIRMATION_STOPPED)
+ ar->radar_conf_state = ATH10K_RADAR_CONFIRMATION_IDLE;
+ spin_unlock_bh(&ar->data_lock);
+}
+
static void ath10k_dfs_radar_report(struct ath10k *ar,
struct wmi_phyerr_ev_arg *phyerr,
const struct phyerr_radar_report *rr,
@@ -3646,8 +3714,10 @@ static void ath10k_dfs_radar_report(stru
u32 reg0, reg1, tsf32l;
struct ieee80211_channel *ch;
struct pulse_event pe;
+ struct radar_detector_specs rs;
u64 tsf64;
u8 rssi, width;
+ struct ath10k_radar_found_info *radar_info;
reg0 = __le32_to_cpu(rr->reg0);
reg1 = __le32_to_cpu(rr->reg1);
@@ -3712,25 +3782,46 @@ static void ath10k_dfs_radar_report(stru
ATH10K_DFS_STAT_INC(ar, pulses_detected);
- if (!ar->dfs_detector->add_pulse(ar->dfs_detector, &pe, NULL)) {
+ if (!ar->dfs_detector->add_pulse(ar->dfs_detector, &pe, &rs)) {
ath10k_dbg(ar, ATH10K_DBG_REGULATORY,
"dfs no pulse pattern detected, yet\n");
return;
}
-radar_detected:
- ath10k_dbg(ar, ATH10K_DBG_REGULATORY, "dfs radar detected\n");
- ATH10K_DFS_STAT_INC(ar, radar_detected);
+ if ((test_bit(WMI_SERVICE_HOST_DFS_CHECK_SUPPORT, ar->wmi.svc_map)) &&
+ ar->dfs_detector->region == NL80211_DFS_FCC) {
+ /* Consecutive radar indications need not be
+ * sent to the firmware until we get confirmation
+ * for the previous detected radar.
+ */
+ spin_lock_bh(&ar->data_lock);
+ if (ar->radar_conf_state != ATH10K_RADAR_CONFIRMATION_IDLE) {
+ spin_unlock_bh(&ar->data_lock);
+ return;
+ }
+ ar->radar_conf_state = ATH10K_RADAR_CONFIRMATION_INPROGRESS;
+ radar_info = &ar->last_radar_info;
- /* Control radar events reporting in debugfs file
- * dfs_block_radar_events
- */
- if (ar->dfs_block_radar_events) {
- ath10k_info(ar, "DFS Radar detected, but ignored as requested\n");
+ radar_info->pri_min = rs.pri_min;
+ radar_info->pri_max = rs.pri_max;
+ radar_info->width_min = rs.width_min;
+ radar_info->width_max = rs.width_max;
+ /*TODO Find sidx_min and sidx_max */
+ radar_info->sidx_min = MS(reg0, RADAR_REPORT_REG0_PULSE_SIDX);
+ radar_info->sidx_max = MS(reg0, RADAR_REPORT_REG0_PULSE_SIDX);
+
+ ath10k_dbg(ar, ATH10K_DBG_REGULATORY,
+ "sending wmi radar found cmd pri_min %d pri_max %d width_min %d width_max %d sidx_min %d sidx_max %d\n",
+ radar_info->pri_min, radar_info->pri_max,
+ radar_info->width_min, radar_info->width_max,
+ radar_info->sidx_min, radar_info->sidx_max);
+ ieee80211_queue_work(ar->hw, &ar->radar_confirmation_work);
+ spin_unlock_bh(&ar->data_lock);
return;
}
- ieee80211_radar_detected(ar->hw);
+radar_detected:
+ ath10k_radar_detected(ar);
}
static int ath10k_dfs_fft_report(struct ath10k *ar,
@@ -4080,6 +4171,47 @@ void ath10k_wmi_event_phyerr(struct ath1
}
}
+static int
+ath10k_wmi_10_4_op_pull_dfs_status_ev(struct ath10k *ar, struct sk_buff *skb,
+ struct wmi_dfs_status_ev_arg *arg)
+{
+ struct wmi_dfs_status_ev_arg *ev = (void *)skb->data;
+
+ if (skb->len < sizeof(*ev))
+ return -EPROTO;
+
+ arg->status = ev->status;
+
+ return 0;
+}
+
+static void
+ath10k_wmi_event_dfs_status_check(struct ath10k *ar, struct sk_buff *skb)
+{
+ struct wmi_dfs_status_ev_arg status_arg = {};
+ int ret;
+
+ ret = ath10k_wmi_pull_dfs_status(ar, skb, &status_arg);
+
+ if (ret) {
+ ath10k_warn(ar, "failed to parse dfs status event: %d\n", ret);
+ return;
+ }
+
+ ath10k_dbg(ar, ATH10K_DBG_REGULATORY,
+ "dfs status event received from fw: %d\n",
+ status_arg.status);
+
+ /* Even in case of radar detection failure we follow the same
+ * behaviour as if radar is detected i.e to switch to a different
+ * channel.
+ */
+ if (status_arg.status == WMI_HW_RADAR_DETECTED ||
+ status_arg.status == WMI_RADAR_DETECTION_FAIL)
+ ath10k_radar_detected(ar);
+ complete(&ar->wmi.radar_confirm);
+}
+
void ath10k_wmi_event_roam(struct ath10k *ar, struct sk_buff *skb)
{
struct wmi_roam_ev_arg arg = {};
@@ -5814,6 +5946,9 @@ static void ath10k_wmi_10_4_op_rx(struct
case WMI_10_4_PDEV_TPC_TABLE_EVENTID:
ath10k_wmi_event_tpc_final_table(ar, skb);
break;
+ case WMI_10_4_DFS_STATUS_CHECK_EVENTID:
+ ath10k_wmi_event_dfs_status_check(ar, skb);
+ break;
default:
ath10k_warn(ar, "Unknown eventid: %d\n", id);
break;
@@ -8332,6 +8467,32 @@ ath10k_wmi_10_4_gen_tdls_peer_update(str
}
static struct sk_buff *
+ath10k_wmi_10_4_gen_radar_found(struct ath10k *ar,
+ const struct ath10k_radar_found_info *arg)
+{
+ struct wmi_radar_found_info *cmd;
+ struct sk_buff *skb;
+
+ skb = ath10k_wmi_alloc_skb(ar, sizeof(*cmd));
+ if (!skb)
+ return ERR_PTR(-ENOMEM);
+
+ cmd = (struct wmi_radar_found_info *)skb->data;
+ cmd->pri_min = __cpu_to_le32(arg->pri_min);
+ cmd->pri_max = __cpu_to_le32(arg->pri_max);
+ cmd->width_min = __cpu_to_le32(arg->width_min);
+ cmd->width_max = __cpu_to_le32(arg->width_max);
+ cmd->sidx_min = __cpu_to_le32(arg->sidx_min);
+ cmd->sidx_max = __cpu_to_le32(arg->sidx_max);
+
+ ath10k_dbg(ar, ATH10K_DBG_WMI,
+ "wmi radar found pri_min %d pri_max %d width_min %d width_max %d sidx_min %d sidx_max %d\n",
+ arg->pri_min, arg->pri_max, arg->width_min,
+ arg->width_max, arg->sidx_min, arg->sidx_max);
+ return skb;
+}
+
+static struct sk_buff *
ath10k_wmi_op_gen_echo(struct ath10k *ar, u32 value)
{
struct wmi_echo_cmd *cmd;
@@ -8668,6 +8829,7 @@ static const struct wmi_ops wmi_10_4_ops
.pull_svc_rdy = ath10k_wmi_main_op_pull_svc_rdy_ev,
.pull_rdy = ath10k_wmi_op_pull_rdy_ev,
.pull_roam_ev = ath10k_wmi_op_pull_roam_ev,
+ .pull_dfs_status_ev = ath10k_wmi_10_4_op_pull_dfs_status_ev,
.get_txbf_conf_scheme = ath10k_wmi_10_4_txbf_conf_scheme,
.gen_pdev_suspend = ath10k_wmi_op_gen_pdev_suspend,
@@ -8714,6 +8876,7 @@ static const struct wmi_ops wmi_10_4_ops
.gen_tdls_peer_update = ath10k_wmi_10_4_gen_tdls_peer_update,
.gen_pdev_get_tpc_table_cmdid =
ath10k_wmi_10_4_op_gen_pdev_get_tpc_table_cmdid,
+ .gen_radar_found = ath10k_wmi_10_4_gen_radar_found,
/* shared with 10.2 */
.pull_echo_ev = ath10k_wmi_op_pull_echo_ev,
@@ -8776,8 +8939,11 @@ int ath10k_wmi_attach(struct ath10k *ar)
init_completion(&ar->wmi.service_ready);
init_completion(&ar->wmi.unified_ready);
init_completion(&ar->wmi.barrier);
+ init_completion(&ar->wmi.radar_confirm);
INIT_WORK(&ar->svc_rdy_work, ath10k_wmi_event_service_ready_work);
+ INIT_WORK(&ar->radar_confirmation_work,
+ ath10k_radar_confirmation_work);
return 0;
}
--- a/drivers/net/wireless/ath/ath10k/wmi.h
+++ b/drivers/net/wireless/ath/ath10k/wmi.h
@@ -959,6 +959,7 @@ struct wmi_cmd_map {
u32 vdev_sifs_trigger_time_cmdid;
u32 pdev_wds_entry_list_cmdid;
u32 tdls_set_offchan_mode_cmdid;
+ u32 radar_found_cmdid;
};
/*
@@ -1792,6 +1793,11 @@ enum wmi_10_4_cmd_id {
WMI_10_4_TDLS_SET_STATE_CMDID,
WMI_10_4_TDLS_PEER_UPDATE_CMDID,
WMI_10_4_TDLS_SET_OFFCHAN_MODE_CMDID,
+ WMI_10_4_PDEV_SEND_FD_CMDID,
+ WMI_10_4_ENABLE_FILS_CMDID,
+ WMI_10_4_PDEV_SET_BRIDGE_MACADDR_CMDID,
+ WMI_10_4_ATF_GROUP_WMM_AC_CONFIG_REQUEST_CMDID,
+ WMI_10_4_RADAR_FOUND_CMDID,
WMI_10_4_PDEV_UTF_CMDID = WMI_10_4_END_CMDID - 1,
};
@@ -1867,6 +1873,9 @@ enum wmi_10_4_event_id {
WMI_10_4_PDEV_TPC_TABLE_EVENTID,
WMI_10_4_PDEV_WDS_ENTRY_LIST_EVENTID,
WMI_10_4_TDLS_PEER_EVENTID,
+ WMI_10_4_HOST_SWFDA_EVENTID,
+ WMI_10_4_ESP_ESTIMATE_EVENTID,
+ WMI_10_4_DFS_STATUS_CHECK_EVENTID,
WMI_10_4_PDEV_UTF_EVENTID = WMI_10_4_END_EVENTID - 1,
};
@@ -3379,6 +3388,25 @@ struct wmi_10_4_phyerr_event {
u8 buf[0];
} __packed;
+struct wmi_radar_found_info {
+ __le32 pri_min;
+ __le32 pri_max;
+ __le32 width_min;
+ __le32 width_max;
+ __le32 sidx_min;
+ __le32 sidx_max;
+} __packed;
+
+enum wmi_radar_confirmation_status {
+ /* Detected radar was due to SW pulses */
+ WMI_SW_RADAR_DETECTED = 0,
+
+ WMI_RADAR_DETECTION_FAIL = 1,
+
+ /* Real radar detected */
+ WMI_HW_RADAR_DETECTED = 2,
+};
+
#define PHYERR_TLV_SIG 0xBB
#define PHYERR_TLV_TAG_SEARCH_FFT_REPORT 0xFB
#define PHYERR_TLV_TAG_RADAR_PULSE_SUMMARY 0xF8
@@ -6586,6 +6614,10 @@ struct wmi_phyerr_hdr_arg {
const void *phyerrs;
};
+struct wmi_dfs_status_ev_arg {
+ u32 status;
+};
+
struct wmi_svc_rdy_ev_arg {
__le32 min_tx_power;
__le32 max_tx_power;