Quelle  calib.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Copyright (C) 2005-2014 Intel Corporation
 */
#include <linux/slab.h>
#include <net/mac80211.h>

#include "iwl-trans.h"

#include "dev.h"
#include "calib.h"
#include "agn.h"

/*****************************************************************************
 * INIT calibrations framework
 *****************************************************************************/

/* Opaque calibration results */
struct iwl_calib_result {
 struct list_head list;
 size_t cmd_len;
 struct iwl_calib_cmd cmd;
};

struct statistics_general_data {
 u32 beacon_silence_rssi_a;
 u32 beacon_silence_rssi_b;
 u32 beacon_silence_rssi_c;
 u32 beacon_energy_a;
 u32 beacon_energy_b;
 u32 beacon_energy_c;
};

int iwl_send_calib_results(struct iwl_priv *priv)
{
 struct iwl_host_cmd hcmd = {
  .id = REPLY_PHY_CALIBRATION_CMD,
 };
 struct iwl_calib_result *res;

 list_for_each_entry(res, &priv->calib_results, list) {
  int ret;

  hcmd.len[0] = res->cmd_len;
  hcmd.data[0] = &res->cmd;
  hcmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
  ret = iwl_dvm_send_cmd(priv, &hcmd);
  if (ret) {
   IWL_ERR(priv, "Error %d on calib cmd %d\n",
    ret, res->cmd.hdr.op_code);
   return ret;
  }
 }

 return 0;
}

int iwl_calib_set(struct iwl_priv *priv,
    const struct iwl_calib_cmd *cmd, size_t len)
{
 struct iwl_calib_result *res, *tmp;

 if (check_sub_overflow(len, sizeof(*cmd), &len))
  return -ENOMEM;

 res = kmalloc(struct_size(res, cmd.data, len), GFP_ATOMIC);
 if (!res)
  return -ENOMEM;
 res->cmd = *cmd;
 memcpy(res->cmd.data, cmd->data, len);
 res->cmd_len = struct_size(cmd, data, len);

 list_for_each_entry(tmp, &priv->calib_results, list) {
  if (tmp->cmd.hdr.op_code == res->cmd.hdr.op_code) {
   list_replace(&tmp->list, &res->list);
   kfree(tmp);
   return 0;
  }
 }

 /* wasn't in list already */
 list_add_tail(&res->list, &priv->calib_results);

 return 0;
}

void iwl_calib_free_results(struct iwl_priv *priv)
{
 struct iwl_calib_result *res, *tmp;

 list_for_each_entry_safe(res, tmp, &priv->calib_results, list) {
  list_del(&res->list);
  kfree(res);
 }
}

/*****************************************************************************
 * RUNTIME calibrations framework
 *****************************************************************************/

/* "false alarms" are signals that our DSP tries to lock onto,
 *   but then determines that they are either noise, or transmissions
 *   from a distant wireless network (also "noise", really) that get
 *   "stepped on" by stronger transmissions within our own network.
 * This algorithm attempts to set a sensitivity level that is high
 *   enough to receive all of our own network traffic, but not so
 *   high that our DSP gets too busy trying to lock onto non-network
 *   activity/noise. */
static int iwl_sens_energy_cck(struct iwl_priv *priv,
       u32 norm_fa,
       u32 rx_enable_time,
       struct statistics_general_data *rx_info)
{
 u32 max_nrg_cck = 0;
 int i = 0;
 u8 max_silence_rssi = 0;
 u32 silence_ref = 0;
 u8 silence_rssi_a = 0;
 u8 silence_rssi_b = 0;
 u8 silence_rssi_c = 0;
 u32 val;

 /* "false_alarms" values below are cross-multiplications to assess the
 *   numbers of false alarms within the measured period of actual Rx
 *   (Rx is off when we're txing), vs the min/max expected false alarms
 *   (some should be expected if rx is sensitive enough) in a
 *   hypothetical listening period of 200 time units (TU), 204.8 msec:
 *
 * MIN_FA/fixed-time < false_alarms/actual-rx-time < MAX_FA/beacon-time
 *
 * */
 u32 false_alarms = norm_fa * 200 * 1024;
 u32 max_false_alarms = MAX_FA_CCK * rx_enable_time;
 u32 min_false_alarms = MIN_FA_CCK * rx_enable_time;
 struct iwl_sensitivity_data *data = NULL;
 const struct iwl_sensitivity_ranges *ranges = priv->hw_params.sens;

 data = &(priv->sensitivity_data);

 data->nrg_auto_corr_silence_diff = 0;

 /* Find max silence rssi among all 3 receivers.
 * This is background noise, which may include transmissions from other
 *    networks, measured during silence before our network's beacon */
 silence_rssi_a = (u8)((rx_info->beacon_silence_rssi_a &
       ALL_BAND_FILTER) >> 8);
 silence_rssi_b = (u8)((rx_info->beacon_silence_rssi_b &
       ALL_BAND_FILTER) >> 8);
 silence_rssi_c = (u8)((rx_info->beacon_silence_rssi_c &
       ALL_BAND_FILTER) >> 8);

 val = max(silence_rssi_b, silence_rssi_c);
 max_silence_rssi = max(silence_rssi_a, (u8) val);

 /* Store silence rssi in 20-beacon history table */
 data->nrg_silence_rssi[data->nrg_silence_idx] = max_silence_rssi;
 data->nrg_silence_idx++;
 if (data->nrg_silence_idx >= NRG_NUM_PREV_STAT_L)
  data->nrg_silence_idx = 0;

 /* Find max silence rssi across 20 beacon history */
 for (i = 0; i < NRG_NUM_PREV_STAT_L; i++) {
  val = data->nrg_silence_rssi[i];
  silence_ref = max(silence_ref, val);
 }
 IWL_DEBUG_CALIB(priv, "silence a %u, b %u, c %u, 20-bcn max %u\n",
   silence_rssi_a, silence_rssi_b, silence_rssi_c,
   silence_ref);

 /* Find max rx energy (min value!) among all 3 receivers,
 *   measured during beacon frame.
 * Save it in 10-beacon history table. */
 i = data->nrg_energy_idx;
 val = min(rx_info->beacon_energy_b, rx_info->beacon_energy_c);
 data->nrg_value[i] = min(rx_info->beacon_energy_a, val);

 data->nrg_energy_idx++;
 if (data->nrg_energy_idx >= 10)
  data->nrg_energy_idx = 0;

 /* Find min rx energy (max value) across 10 beacon history.
 * This is the minimum signal level that we want to receive well.
 * Add backoff (margin so we don't miss slightly lower energy frames).
 * This establishes an upper bound (min value) for energy threshold. */
 max_nrg_cck = data->nrg_value[0];
 for (i = 1; i < 10; i++)
  max_nrg_cck = (u32) max(max_nrg_cck, (data->nrg_value[i]));
 max_nrg_cck += 6;

 IWL_DEBUG_CALIB(priv, "rx energy a %u, b %u, c %u, 10-bcn max/min %u\n",
   rx_info->beacon_energy_a, rx_info->beacon_energy_b,
   rx_info->beacon_energy_c, max_nrg_cck - 6);

 /* Count number of consecutive beacons with fewer-than-desired
 *   false alarms. */
 if (false_alarms < min_false_alarms)
  data->num_in_cck_no_fa++;
 else
  data->num_in_cck_no_fa = 0;
 IWL_DEBUG_CALIB(priv, "consecutive bcns with few false alarms = %u\n",
   data->num_in_cck_no_fa);

 /* If we got too many false alarms this time, reduce sensitivity */
 if ((false_alarms > max_false_alarms) &&
  (data->auto_corr_cck > AUTO_CORR_MAX_TH_CCK)) {
  IWL_DEBUG_CALIB(priv, "norm FA %u > max FA %u\n",
       false_alarms, max_false_alarms);
  IWL_DEBUG_CALIB(priv, "... reducing sensitivity\n");
  data->nrg_curr_state = IWL_FA_TOO_MANY;
  /* Store for "fewer than desired" on later beacon */
  data->nrg_silence_ref = silence_ref;

  /* increase energy threshold (reduce nrg value)
 *   to decrease sensitivity */
  data->nrg_th_cck = data->nrg_th_cck - NRG_STEP_CCK;
 /* Else if we got fewer than desired, increase sensitivity */
 } else if (false_alarms < min_false_alarms) {
  data->nrg_curr_state = IWL_FA_TOO_FEW;

  /* Compare silence level with silence level for most recent
 *   healthy number or too many false alarms */
  data->nrg_auto_corr_silence_diff = (s32)data->nrg_silence_ref -
         (s32)silence_ref;

  IWL_DEBUG_CALIB(priv, "norm FA %u < min FA %u, silence diff %d\n",
    false_alarms, min_false_alarms,
    data->nrg_auto_corr_silence_diff);

  /* Increase value to increase sensitivity, but only if:
 * 1a) previous beacon did *not* have *too many* false alarms
 * 1b) AND there's a significant difference in Rx levels
 *      from a previous beacon with too many, or healthy # FAs
 * OR 2) We've seen a lot of beacons (100) with too few
 *       false alarms */
  if ((data->nrg_prev_state != IWL_FA_TOO_MANY) &&
   ((data->nrg_auto_corr_silence_diff > NRG_DIFF) ||
   (data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA))) {

   IWL_DEBUG_CALIB(priv, "... increasing sensitivity\n");
   /* Increase nrg value to increase sensitivity */
   val = data->nrg_th_cck + NRG_STEP_CCK;
   data->nrg_th_cck = min((u32)ranges->min_nrg_cck, val);
  } else {
   IWL_DEBUG_CALIB(priv, "... but not changing sensitivity\n");
  }

 /* Else we got a healthy number of false alarms, keep status quo */
 } else {
  IWL_DEBUG_CALIB(priv, " FA in safe zone\n");
  data->nrg_curr_state = IWL_FA_GOOD_RANGE;

  /* Store for use in "fewer than desired" with later beacon */
  data->nrg_silence_ref = silence_ref;

  /* If previous beacon had too many false alarms,
 *   give it some extra margin by reducing sensitivity again
 *   (but don't go below measured energy of desired Rx) */
  if (data->nrg_prev_state == IWL_FA_TOO_MANY) {
   IWL_DEBUG_CALIB(priv, "... increasing margin\n");
   if (data->nrg_th_cck > (max_nrg_cck + NRG_MARGIN))
    data->nrg_th_cck -= NRG_MARGIN;
   else
    data->nrg_th_cck = max_nrg_cck;
  }
 }

 /* Make sure the energy threshold does not go above the measured
 * energy of the desired Rx signals (reduced by backoff margin),
 * or else we might start missing Rx frames.
 * Lower value is higher energy, so we use max()!
 */
 data->nrg_th_cck = max(max_nrg_cck, data->nrg_th_cck);
 IWL_DEBUG_CALIB(priv, "new nrg_th_cck %u\n", data->nrg_th_cck);

 data->nrg_prev_state = data->nrg_curr_state;

 /* Auto-correlation CCK algorithm */
 if (false_alarms > min_false_alarms) {

  /* increase auto_corr values to decrease sensitivity
 * so the DSP won't be disturbed by the noise
 */
  if (data->auto_corr_cck < AUTO_CORR_MAX_TH_CCK)
   data->auto_corr_cck = AUTO_CORR_MAX_TH_CCK + 1;
  else {
   val = data->auto_corr_cck + AUTO_CORR_STEP_CCK;
   data->auto_corr_cck =
    min((u32)ranges->auto_corr_max_cck, val);
  }
  val = data->auto_corr_cck_mrc + AUTO_CORR_STEP_CCK;
  data->auto_corr_cck_mrc =
   min((u32)ranges->auto_corr_max_cck_mrc, val);
 } else if ((false_alarms < min_false_alarms) &&
    ((data->nrg_auto_corr_silence_diff > NRG_DIFF) ||
    (data->num_in_cck_no_fa > MAX_NUMBER_CCK_NO_FA))) {

  /* Decrease auto_corr values to increase sensitivity */
  val = data->auto_corr_cck - AUTO_CORR_STEP_CCK;
  data->auto_corr_cck =
   max((u32)ranges->auto_corr_min_cck, val);
  val = data->auto_corr_cck_mrc - AUTO_CORR_STEP_CCK;
  data->auto_corr_cck_mrc =
   max((u32)ranges->auto_corr_min_cck_mrc, val);
 }

 return 0;
}


static int iwl_sens_auto_corr_ofdm(struct iwl_priv *priv,
           u32 norm_fa,
           u32 rx_enable_time)
{
 u32 val;
 u32 false_alarms = norm_fa * 200 * 1024;
 u32 max_false_alarms = MAX_FA_OFDM * rx_enable_time;
 u32 min_false_alarms = MIN_FA_OFDM * rx_enable_time;
 struct iwl_sensitivity_data *data = NULL;
 const struct iwl_sensitivity_ranges *ranges = priv->hw_params.sens;

 data = &(priv->sensitivity_data);

 /* If we got too many false alarms this time, reduce sensitivity */
 if (false_alarms > max_false_alarms) {

  IWL_DEBUG_CALIB(priv, "norm FA %u > max FA %u)\n",
        false_alarms, max_false_alarms);

  val = data->auto_corr_ofdm + AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm =
   min((u32)ranges->auto_corr_max_ofdm, val);

  val = data->auto_corr_ofdm_mrc + AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm_mrc =
   min((u32)ranges->auto_corr_max_ofdm_mrc, val);

  val = data->auto_corr_ofdm_x1 + AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm_x1 =
   min((u32)ranges->auto_corr_max_ofdm_x1, val);

  val = data->auto_corr_ofdm_mrc_x1 + AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm_mrc_x1 =
   min((u32)ranges->auto_corr_max_ofdm_mrc_x1, val);
 }

 /* Else if we got fewer than desired, increase sensitivity */
 else if (false_alarms < min_false_alarms) {

  IWL_DEBUG_CALIB(priv, "norm FA %u < min FA %u\n",
        false_alarms, min_false_alarms);

  val = data->auto_corr_ofdm - AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm =
   max((u32)ranges->auto_corr_min_ofdm, val);

  val = data->auto_corr_ofdm_mrc - AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm_mrc =
   max((u32)ranges->auto_corr_min_ofdm_mrc, val);

  val = data->auto_corr_ofdm_x1 - AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm_x1 =
   max((u32)ranges->auto_corr_min_ofdm_x1, val);

  val = data->auto_corr_ofdm_mrc_x1 - AUTO_CORR_STEP_OFDM;
  data->auto_corr_ofdm_mrc_x1 =
   max((u32)ranges->auto_corr_min_ofdm_mrc_x1, val);
 } else {
  IWL_DEBUG_CALIB(priv, "min FA %u < norm FA %u < max FA %u OK\n",
    min_false_alarms, false_alarms, max_false_alarms);
 }
 return 0;
}

static void iwl_prepare_legacy_sensitivity_tbl(struct iwl_priv *priv,
    struct iwl_sensitivity_data *data,
    __le16 *tbl)
{
 tbl[HD_AUTO_CORR32_X4_TH_ADD_MIN_INDEX] =
    cpu_to_le16((u16)data->auto_corr_ofdm);
 tbl[HD_AUTO_CORR32_X4_TH_ADD_MIN_MRC_INDEX] =
    cpu_to_le16((u16)data->auto_corr_ofdm_mrc);
 tbl[HD_AUTO_CORR32_X1_TH_ADD_MIN_INDEX] =
    cpu_to_le16((u16)data->auto_corr_ofdm_x1);
 tbl[HD_AUTO_CORR32_X1_TH_ADD_MIN_MRC_INDEX] =
    cpu_to_le16((u16)data->auto_corr_ofdm_mrc_x1);

 tbl[HD_AUTO_CORR40_X4_TH_ADD_MIN_INDEX] =
    cpu_to_le16((u16)data->auto_corr_cck);
 tbl[HD_AUTO_CORR40_X4_TH_ADD_MIN_MRC_INDEX] =
    cpu_to_le16((u16)data->auto_corr_cck_mrc);

 tbl[HD_MIN_ENERGY_CCK_DET_INDEX] =
    cpu_to_le16((u16)data->nrg_th_cck);
 tbl[HD_MIN_ENERGY_OFDM_DET_INDEX] =
    cpu_to_le16((u16)data->nrg_th_ofdm);

 tbl[HD_BARKER_CORR_TH_ADD_MIN_INDEX] =
    cpu_to_le16(data->barker_corr_th_min);
 tbl[HD_BARKER_CORR_TH_ADD_MIN_MRC_INDEX] =
    cpu_to_le16(data->barker_corr_th_min_mrc);
 tbl[HD_OFDM_ENERGY_TH_IN_INDEX] =
    cpu_to_le16(data->nrg_th_cca);

 IWL_DEBUG_CALIB(priv, "ofdm: ac %u mrc %u x1 %u mrc_x1 %u thresh %u\n",
   data->auto_corr_ofdm, data->auto_corr_ofdm_mrc,
   data->auto_corr_ofdm_x1, data->auto_corr_ofdm_mrc_x1,
   data->nrg_th_ofdm);

 IWL_DEBUG_CALIB(priv, "cck: ac %u mrc %u thresh %u\n",
   data->auto_corr_cck, data->auto_corr_cck_mrc,
   data->nrg_th_cck);
}

/* Prepare a SENSITIVITY_CMD, send to uCode if values have changed */
static int iwl_sensitivity_write(struct iwl_priv *priv)
{
 struct iwl_sensitivity_cmd cmd;
 struct iwl_sensitivity_data *data = NULL;
 struct iwl_host_cmd cmd_out = {
  .id = SENSITIVITY_CMD,
  .len = { sizeof(struct iwl_sensitivity_cmd), },
  .flags = CMD_ASYNC,
  .data = { &cmd, },
 };

 data = &(priv->sensitivity_data);

 memset(&cmd, 0, sizeof(cmd));

 iwl_prepare_legacy_sensitivity_tbl(priv, data, &cmd.table[0]);

 /* Update uCode's "work" table, and copy it to DSP */
 cmd.control = SENSITIVITY_CMD_CONTROL_WORK_TABLE;

 /* Don't send command to uCode if nothing has changed */
 if (!memcmp(&cmd.table[0], &(priv->sensitivity_tbl[0]),
      sizeof(u16)*HD_TABLE_SIZE)) {
  IWL_DEBUG_CALIB(priv, "No change in SENSITIVITY_CMD\n");
  return 0;
 }

 /* Copy table for comparison next time */
 memcpy(&(priv->sensitivity_tbl[0]), &(cmd.table[0]),
        sizeof(u16)*HD_TABLE_SIZE);

 return iwl_dvm_send_cmd(priv, &cmd_out);
}

/* Prepare a SENSITIVITY_CMD, send to uCode if values have changed */
static int iwl_enhance_sensitivity_write(struct iwl_priv *priv)
{
 struct iwl_enhance_sensitivity_cmd cmd;
 struct iwl_sensitivity_data *data = NULL;
 struct iwl_host_cmd cmd_out = {
  .id = SENSITIVITY_CMD,
  .len = { sizeof(struct iwl_enhance_sensitivity_cmd), },
  .flags = CMD_ASYNC,
  .data = { &cmd, },
 };

 data = &(priv->sensitivity_data);

 memset(&cmd, 0, sizeof(cmd));

 iwl_prepare_legacy_sensitivity_tbl(priv, data, &cmd.enhance_table[0]);

 if (priv->lib->hd_v2) {
  cmd.enhance_table[HD_INA_NON_SQUARE_DET_OFDM_INDEX] =
   HD_INA_NON_SQUARE_DET_OFDM_DATA_V2;
  cmd.enhance_table[HD_INA_NON_SQUARE_DET_CCK_INDEX] =
   HD_INA_NON_SQUARE_DET_CCK_DATA_V2;
  cmd.enhance_table[HD_CORR_11_INSTEAD_OF_CORR_9_EN_INDEX] =
   HD_CORR_11_INSTEAD_OF_CORR_9_EN_DATA_V2;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_SLOPE_MRC_INDEX] =
   HD_OFDM_NON_SQUARE_DET_SLOPE_MRC_DATA_V2;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_INTERCEPT_MRC_INDEX] =
   HD_OFDM_NON_SQUARE_DET_INTERCEPT_MRC_DATA_V2;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_SLOPE_INDEX] =
   HD_OFDM_NON_SQUARE_DET_SLOPE_DATA_V2;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_INTERCEPT_INDEX] =
   HD_OFDM_NON_SQUARE_DET_INTERCEPT_DATA_V2;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_SLOPE_MRC_INDEX] =
   HD_CCK_NON_SQUARE_DET_SLOPE_MRC_DATA_V2;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_INTERCEPT_MRC_INDEX] =
   HD_CCK_NON_SQUARE_DET_INTERCEPT_MRC_DATA_V2;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_SLOPE_INDEX] =
   HD_CCK_NON_SQUARE_DET_SLOPE_DATA_V2;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_INTERCEPT_INDEX] =
   HD_CCK_NON_SQUARE_DET_INTERCEPT_DATA_V2;
 } else {
  cmd.enhance_table[HD_INA_NON_SQUARE_DET_OFDM_INDEX] =
   HD_INA_NON_SQUARE_DET_OFDM_DATA_V1;
  cmd.enhance_table[HD_INA_NON_SQUARE_DET_CCK_INDEX] =
   HD_INA_NON_SQUARE_DET_CCK_DATA_V1;
  cmd.enhance_table[HD_CORR_11_INSTEAD_OF_CORR_9_EN_INDEX] =
   HD_CORR_11_INSTEAD_OF_CORR_9_EN_DATA_V1;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_SLOPE_MRC_INDEX] =
   HD_OFDM_NON_SQUARE_DET_SLOPE_MRC_DATA_V1;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_INTERCEPT_MRC_INDEX] =
   HD_OFDM_NON_SQUARE_DET_INTERCEPT_MRC_DATA_V1;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_SLOPE_INDEX] =
   HD_OFDM_NON_SQUARE_DET_SLOPE_DATA_V1;
  cmd.enhance_table[HD_OFDM_NON_SQUARE_DET_INTERCEPT_INDEX] =
   HD_OFDM_NON_SQUARE_DET_INTERCEPT_DATA_V1;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_SLOPE_MRC_INDEX] =
   HD_CCK_NON_SQUARE_DET_SLOPE_MRC_DATA_V1;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_INTERCEPT_MRC_INDEX] =
   HD_CCK_NON_SQUARE_DET_INTERCEPT_MRC_DATA_V1;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_SLOPE_INDEX] =
   HD_CCK_NON_SQUARE_DET_SLOPE_DATA_V1;
  cmd.enhance_table[HD_CCK_NON_SQUARE_DET_INTERCEPT_INDEX] =
   HD_CCK_NON_SQUARE_DET_INTERCEPT_DATA_V1;
 }

 /* Update uCode's "work" table, and copy it to DSP */
 cmd.control = SENSITIVITY_CMD_CONTROL_WORK_TABLE;

 /* Don't send command to uCode if nothing has changed */
 if (!memcmp(&cmd.enhance_table[0], &(priv->sensitivity_tbl[0]),
      sizeof(u16)*HD_TABLE_SIZE) &&
     !memcmp(&cmd.enhance_table[HD_INA_NON_SQUARE_DET_OFDM_INDEX],
      &(priv->enhance_sensitivity_tbl[0]),
      sizeof(u16)*ENHANCE_HD_TABLE_ENTRIES)) {
  IWL_DEBUG_CALIB(priv, "No change in SENSITIVITY_CMD\n");
  return 0;
 }

 /* Copy table for comparison next time */
 memcpy(&(priv->sensitivity_tbl[0]), &(cmd.enhance_table[0]),
        sizeof(u16)*HD_TABLE_SIZE);
 memcpy(&(priv->enhance_sensitivity_tbl[0]),
        &(cmd.enhance_table[HD_INA_NON_SQUARE_DET_OFDM_INDEX]),
        sizeof(u16)*ENHANCE_HD_TABLE_ENTRIES);

 return iwl_dvm_send_cmd(priv, &cmd_out);
}

void iwl_init_sensitivity(struct iwl_priv *priv)
{
 int ret = 0;
 int i;
 struct iwl_sensitivity_data *data = NULL;
 const struct iwl_sensitivity_ranges *ranges = priv->hw_params.sens;

 if (priv->calib_disabled & IWL_SENSITIVITY_CALIB_DISABLED)
  return;

 IWL_DEBUG_CALIB(priv, "Start iwl_init_sensitivity\n");

 /* Clear driver's sensitivity algo data */
 data = &(priv->sensitivity_data);

 if (ranges == NULL)
  return;

 memset(data, 0, sizeof(struct iwl_sensitivity_data));

 data->num_in_cck_no_fa = 0;
 data->nrg_curr_state = IWL_FA_TOO_MANY;
 data->nrg_prev_state = IWL_FA_TOO_MANY;
 data->nrg_silence_ref = 0;
 data->nrg_silence_idx = 0;
 data->nrg_energy_idx = 0;

 for (i = 0; i < 10; i++)
  data->nrg_value[i] = 0;

 for (i = 0; i < NRG_NUM_PREV_STAT_L; i++)
  data->nrg_silence_rssi[i] = 0;

 data->auto_corr_ofdm =  ranges->auto_corr_min_ofdm;
 data->auto_corr_ofdm_mrc = ranges->auto_corr_min_ofdm_mrc;
 data->auto_corr_ofdm_x1  = ranges->auto_corr_min_ofdm_x1;
 data->auto_corr_ofdm_mrc_x1 = ranges->auto_corr_min_ofdm_mrc_x1;
 data->auto_corr_cck = AUTO_CORR_CCK_MIN_VAL_DEF;
 data->auto_corr_cck_mrc = ranges->auto_corr_min_cck_mrc;
 data->nrg_th_cck = ranges->nrg_th_cck;
 data->nrg_th_ofdm = ranges->nrg_th_ofdm;
 data->barker_corr_th_min = ranges->barker_corr_th_min;
 data->barker_corr_th_min_mrc = ranges->barker_corr_th_min_mrc;
 data->nrg_th_cca = ranges->nrg_th_cca;

 data->last_bad_plcp_cnt_ofdm = 0;
 data->last_fa_cnt_ofdm = 0;
 data->last_bad_plcp_cnt_cck = 0;
 data->last_fa_cnt_cck = 0;

 if (priv->fw->enhance_sensitivity_table)
  ret |= iwl_enhance_sensitivity_write(priv);
 else
  ret |= iwl_sensitivity_write(priv);
 IWL_DEBUG_CALIB(priv, "<, ret);
}

void iwl_sensitivity_calibration(struct iwl_priv *priv)
{
 u32 rx_enable_time;
 u32 fa_cck;
 u32 fa_ofdm;
 u32 bad_plcp_cck;
 u32 bad_plcp_ofdm;
 u32 norm_fa_ofdm;
 u32 norm_fa_cck;
 struct iwl_sensitivity_data *data = NULL;
 struct statistics_rx_non_phy *rx_info;
 struct statistics_rx_phy *ofdm, *cck;
 struct statistics_general_data statis;

 if (priv->calib_disabled & IWL_SENSITIVITY_CALIB_DISABLED)
  return;

 data = &(priv->sensitivity_data);

 if (!iwl_is_any_associated(priv)) {
  IWL_DEBUG_CALIB(priv, "<< - not associated\n");
  return;
 }

 spin_lock_bh(&priv->statistics.lock);
 rx_info = &priv->statistics.rx_non_phy;
 ofdm = &priv->statistics.rx_ofdm;
 cck = &priv->statistics.rx_cck;
 if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
  IWL_DEBUG_CALIB(priv, "<< invalid data.\n");
  spin_unlock_bh(&priv->statistics.lock);
  return;
 }

 /* Extract Statistics: */
 rx_enable_time = le32_to_cpu(rx_info->channel_load);
 fa_cck = le32_to_cpu(cck->false_alarm_cnt);
 fa_ofdm = le32_to_cpu(ofdm->false_alarm_cnt);
 bad_plcp_cck = le32_to_cpu(cck->plcp_err);
 bad_plcp_ofdm = le32_to_cpu(ofdm->plcp_err);

 statis.beacon_silence_rssi_a =
   le32_to_cpu(rx_info->beacon_silence_rssi_a);
 statis.beacon_silence_rssi_b =
   le32_to_cpu(rx_info->beacon_silence_rssi_b);
 statis.beacon_silence_rssi_c =
   le32_to_cpu(rx_info->beacon_silence_rssi_c);
 statis.beacon_energy_a =
   le32_to_cpu(rx_info->beacon_energy_a);
 statis.beacon_energy_b =
   le32_to_cpu(rx_info->beacon_energy_b);
 statis.beacon_energy_c =
   le32_to_cpu(rx_info->beacon_energy_c);

 spin_unlock_bh(&priv->statistics.lock);

 IWL_DEBUG_CALIB(priv, "rx_enable_time = %u usecs\n", rx_enable_time);

 if (!rx_enable_time) {
  IWL_DEBUG_CALIB(priv, "<< RX Enable Time == 0!\n");
  return;
 }

 /* These statistics increase monotonically, and do not reset
 *   at each beacon.  Calculate difference from last value, or just
 *   use the new statistics value if it has reset or wrapped around. */
 if (data->last_bad_plcp_cnt_cck > bad_plcp_cck)
  data->last_bad_plcp_cnt_cck = bad_plcp_cck;
 else {
  bad_plcp_cck -= data->last_bad_plcp_cnt_cck;
  data->last_bad_plcp_cnt_cck += bad_plcp_cck;
 }

 if (data->last_bad_plcp_cnt_ofdm > bad_plcp_ofdm)
  data->last_bad_plcp_cnt_ofdm = bad_plcp_ofdm;
 else {
  bad_plcp_ofdm -= data->last_bad_plcp_cnt_ofdm;
  data->last_bad_plcp_cnt_ofdm += bad_plcp_ofdm;
 }

 if (data->last_fa_cnt_ofdm > fa_ofdm)
  data->last_fa_cnt_ofdm = fa_ofdm;
 else {
  fa_ofdm -= data->last_fa_cnt_ofdm;
  data->last_fa_cnt_ofdm += fa_ofdm;
 }

 if (data->last_fa_cnt_cck > fa_cck)
  data->last_fa_cnt_cck = fa_cck;
 else {
  fa_cck -= data->last_fa_cnt_cck;
  data->last_fa_cnt_cck += fa_cck;
 }

 /* Total aborted signal locks */
 norm_fa_ofdm = fa_ofdm + bad_plcp_ofdm;
 norm_fa_cck = fa_cck + bad_plcp_cck;

 IWL_DEBUG_CALIB(priv, "cck: fa %u badp %u ofdm: fa %u badp %u\n", fa_cck,
   bad_plcp_cck, fa_ofdm, bad_plcp_ofdm);

 iwl_sens_auto_corr_ofdm(priv, norm_fa_ofdm, rx_enable_time);
 iwl_sens_energy_cck(priv, norm_fa_cck, rx_enable_time, &statis);
 if (priv->fw->enhance_sensitivity_table)
  iwl_enhance_sensitivity_write(priv);
 else
  iwl_sensitivity_write(priv);
}

static inline u8 find_first_chain(u8 mask)
{
 if (mask & ANT_A)
  return CHAIN_A;
 if (mask & ANT_B)
  return CHAIN_B;
 return CHAIN_C;
}

/*
 * Run disconnected antenna algorithm to find out which antennas are
 * disconnected.
 */
static void iwl_find_disconn_antenna(struct iwl_priv *priv, u32* average_sig,
         struct iwl_chain_noise_data *data)
{
 u32 active_chains = 0;
 u32 max_average_sig;
 u16 max_average_sig_antenna_i;
 u8 num_tx_chains;
 u8 first_chain;
 u16 i = 0;

 average_sig[0] = data->chain_signal_a / IWL_CAL_NUM_BEACONS;
 average_sig[1] = data->chain_signal_b / IWL_CAL_NUM_BEACONS;
 average_sig[2] = data->chain_signal_c / IWL_CAL_NUM_BEACONS;

 if (average_sig[0] >= average_sig[1]) {
  max_average_sig = average_sig[0];
  max_average_sig_antenna_i = 0;
  active_chains = (1 << max_average_sig_antenna_i);
 } else {
  max_average_sig = average_sig[1];
  max_average_sig_antenna_i = 1;
  active_chains = (1 << max_average_sig_antenna_i);
 }

 if (average_sig[2] >= max_average_sig) {
  max_average_sig = average_sig[2];
  max_average_sig_antenna_i = 2;
  active_chains = (1 << max_average_sig_antenna_i);
 }

 IWL_DEBUG_CALIB(priv, "average_sig: a %d b %d c %d\n",
       average_sig[0], average_sig[1], average_sig[2]);
 IWL_DEBUG_CALIB(priv, "max_average_sig = %d, antenna %d\n",
       max_average_sig, max_average_sig_antenna_i);

 /* Compare signal strengths for all 3 receivers. */
 for (i = 0; i < NUM_RX_CHAINS; i++) {
  if (i != max_average_sig_antenna_i) {
   s32 rssi_delta = (max_average_sig - average_sig[i]);

   /* If signal is very weak, compared with
 * strongest, mark it as disconnected. */
   if (rssi_delta > MAXIMUM_ALLOWED_PATHLOSS)
    data->disconn_array[i] = 1;
   else
    active_chains |= (1 << i);
   IWL_DEBUG_CALIB(priv, "i = %d rssiDelta = %d "
        "disconn_array[i] = %d\n",
        i, rssi_delta, data->disconn_array[i]);
  }
 }

 /*
 * The above algorithm sometimes fails when the ucode
 * reports 0 for all chains. It's not clear why that
 * happens to start with, but it is then causing trouble
 * because this can make us enable more chains than the
 * hardware really has.
 *
 * To be safe, simply mask out any chains that we know
 * are not on the device.
 */
 active_chains &= priv->nvm_data->valid_rx_ant;

 num_tx_chains = 0;
 for (i = 0; i < NUM_RX_CHAINS; i++) {
  /* loops on all the bits of
 * priv->hw_setting.valid_tx_ant */
  u8 ant_msk = (1 << i);
  if (!(priv->nvm_data->valid_tx_ant & ant_msk))
   continue;

  num_tx_chains++;
  if (data->disconn_array[i] == 0)
   /* there is a Tx antenna connected */
   break;
  if (num_tx_chains == priv->hw_params.tx_chains_num &&
      data->disconn_array[i]) {
   /*
 * If all chains are disconnected
 * connect the first valid tx chain
 */
   first_chain =
    find_first_chain(priv->nvm_data->valid_tx_ant);
   data->disconn_array[first_chain] = 0;
   active_chains |= BIT(first_chain);
   IWL_DEBUG_CALIB(priv,
     "All Tx chains are disconnected W/A - declare %d as connected\n",
     first_chain);
   break;
  }
 }

 if (active_chains != priv->nvm_data->valid_rx_ant &&
     active_chains != priv->chain_noise_data.active_chains)
  IWL_DEBUG_CALIB(priv,
    "Detected that not all antennas are connected! "
    "Connected: %#x, valid: %#x.\n",
    active_chains,
    priv->nvm_data->valid_rx_ant);

 /* Save for use within RXON, TX, SCAN commands, etc. */
 data->active_chains = active_chains;
 IWL_DEBUG_CALIB(priv, "active_chains (bitwise) = 0x%x\n",
   active_chains);
}

static void iwlagn_gain_computation(struct iwl_priv *priv,
        u32 average_noise[NUM_RX_CHAINS],
        u8 default_chain)
{
 int i;
 s32 delta_g;
 struct iwl_chain_noise_data *data = &priv->chain_noise_data;

 /*
 * Find Gain Code for the chains based on "default chain"
 */
 for (i = default_chain + 1; i < NUM_RX_CHAINS; i++) {
  if ((data->disconn_array[i])) {
   data->delta_gain_code[i] = 0;
   continue;
  }

  delta_g = (priv->lib->chain_noise_scale *
   ((s32)average_noise[default_chain] -
   (s32)average_noise[i])) / 1500;

  /* bound gain by 2 bits value max, 3rd bit is sign */
  data->delta_gain_code[i] =
   min(abs(delta_g), CHAIN_NOISE_MAX_DELTA_GAIN_CODE);

  if (delta_g < 0)
   /*
 * set negative sign ...
 * note to Intel developers:  This is uCode API format,
 *   not the format of any internal device registers.
 *   Do not change this format for e.g. 6050 or similar
 *   devices.  Change format only if more resolution
 *   (i.e. more than 2 bits magnitude) is needed.
 */
   data->delta_gain_code[i] |= (1 << 2);
 }

 IWL_DEBUG_CALIB(priv, "Delta gains: ANT_B = %d ANT_C = %d\n",
   data->delta_gain_code[1], data->delta_gain_code[2]);

 if (!data->radio_write) {
  struct iwl_calib_chain_noise_gain_cmd cmd;

  memset(&cmd, 0, sizeof(cmd));

  iwl_set_calib_hdr(&cmd.hdr,
   priv->phy_calib_chain_noise_gain_cmd);
  cmd.delta_gain_1 = data->delta_gain_code[1];
  cmd.delta_gain_2 = data->delta_gain_code[2];
  iwl_dvm_send_cmd_pdu(priv, REPLY_PHY_CALIBRATION_CMD,
   CMD_ASYNC, sizeof(cmd), &cmd);

  data->radio_write = 1;
  data->state = IWL_CHAIN_NOISE_CALIBRATED;
 }
}

/*
 * Accumulate 16 beacons of signal and noise statistics for each of
 *   3 receivers/antennas/rx-chains, then figure out:
 * 1)  Which antennas are connected.
 * 2)  Differential rx gain settings to balance the 3 receivers.
 */
void iwl_chain_noise_calibration(struct iwl_priv *priv)
{
 struct iwl_chain_noise_data *data = NULL;

 u32 chain_noise_a;
 u32 chain_noise_b;
 u32 chain_noise_c;
 u32 chain_sig_a;
 u32 chain_sig_b;
 u32 chain_sig_c;
 u32 average_sig[NUM_RX_CHAINS] = {INITIALIZATION_VALUE};
 u32 average_noise[NUM_RX_CHAINS] = {INITIALIZATION_VALUE};
 u32 min_average_noise = MIN_AVERAGE_NOISE_MAX_VALUE;
 u16 min_average_noise_antenna_i = INITIALIZATION_VALUE;
 u16 i = 0;
 u16 rxon_chnum = INITIALIZATION_VALUE;
 u16 stat_chnum = INITIALIZATION_VALUE;
 u8 rxon_band24;
 u8 stat_band24;
 struct statistics_rx_non_phy *rx_info;

 /*
 * MULTI-FIXME:
 * When we support multiple interfaces on different channels,
 * this must be modified/fixed.
 */
 struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];

 if (priv->calib_disabled & IWL_CHAIN_NOISE_CALIB_DISABLED)
  return;

 data = &(priv->chain_noise_data);

 /*
 * Accumulate just the first "chain_noise_num_beacons" after
 * the first association, then we're done forever.
 */
 if (data->state != IWL_CHAIN_NOISE_ACCUMULATE) {
  if (data->state == IWL_CHAIN_NOISE_ALIVE)
   IWL_DEBUG_CALIB(priv, "Wait for noise calib reset\n");
  return;
 }

 spin_lock_bh(&priv->statistics.lock);

 rx_info = &priv->statistics.rx_non_phy;

 if (rx_info->interference_data_flag != INTERFERENCE_DATA_AVAILABLE) {
  IWL_DEBUG_CALIB(priv, " << Interference data unavailable\n");
  spin_unlock_bh(&priv->statistics.lock);
  return;
 }

 rxon_band24 = !!(ctx->staging.flags & RXON_FLG_BAND_24G_MSK);
 rxon_chnum = le16_to_cpu(ctx->staging.channel);
 stat_band24 =
  !!(priv->statistics.flag & STATISTICS_REPLY_FLG_BAND_24G_MSK);
 stat_chnum = le32_to_cpu(priv->statistics.flag) >> 16;

 /* Make sure we accumulate data for just the associated channel
 *   (even if scanning). */
 if ((rxon_chnum != stat_chnum) || (rxon_band24 != stat_band24)) {
  IWL_DEBUG_CALIB(priv, "Stats not from chan=%d, band24=%d\n",
    rxon_chnum, rxon_band24);
  spin_unlock_bh(&priv->statistics.lock);
  return;
 }

 /*
 *  Accumulate beacon statistics values across
 * "chain_noise_num_beacons"
 */
 chain_noise_a = le32_to_cpu(rx_info->beacon_silence_rssi_a) &
    IN_BAND_FILTER;
 chain_noise_b = le32_to_cpu(rx_info->beacon_silence_rssi_b) &
    IN_BAND_FILTER;
 chain_noise_c = le32_to_cpu(rx_info->beacon_silence_rssi_c) &
    IN_BAND_FILTER;

 chain_sig_a = le32_to_cpu(rx_info->beacon_rssi_a) & IN_BAND_FILTER;
 chain_sig_b = le32_to_cpu(rx_info->beacon_rssi_b) & IN_BAND_FILTER;
 chain_sig_c = le32_to_cpu(rx_info->beacon_rssi_c) & IN_BAND_FILTER;

 spin_unlock_bh(&priv->statistics.lock);

 data->beacon_count++;

 data->chain_noise_a = (chain_noise_a + data->chain_noise_a);
 data->chain_noise_b = (chain_noise_b + data->chain_noise_b);
 data->chain_noise_c = (chain_noise_c + data->chain_noise_c);

 data->chain_signal_a = (chain_sig_a + data->chain_signal_a);
 data->chain_signal_b = (chain_sig_b + data->chain_signal_b);
 data->chain_signal_c = (chain_sig_c + data->chain_signal_c);

 IWL_DEBUG_CALIB(priv, "chan=%d, band24=%d, beacon=%d\n",
   rxon_chnum, rxon_band24, data->beacon_count);
 IWL_DEBUG_CALIB(priv, "chain_sig: a %d b %d c %d\n",
   chain_sig_a, chain_sig_b, chain_sig_c);
 IWL_DEBUG_CALIB(priv, "chain_noise: a %d b %d c %d\n",
   chain_noise_a, chain_noise_b, chain_noise_c);

 /* If this is the "chain_noise_num_beacons", determine:
 * 1)  Disconnected antennas (using signal strengths)
 * 2)  Differential gain (using silence noise) to balance receivers */
 if (data->beacon_count != IWL_CAL_NUM_BEACONS)
  return;

 /* Analyze signal for disconnected antenna */
 if (priv->lib->bt_params &&
     priv->lib->bt_params->advanced_bt_coexist) {
  /* Disable disconnected antenna algorithm for advanced
   bt coex, assuming valid antennas are connected */
  data->active_chains = priv->nvm_data->valid_rx_ant;
  for (i = 0; i < NUM_RX_CHAINS; i++)
   if (!(data->active_chains & (1<<i)))
    data->disconn_array[i] = 1;
 } else
  iwl_find_disconn_antenna(priv, average_sig, data);

 /* Analyze noise for rx balance */
 average_noise[0] = data->chain_noise_a / IWL_CAL_NUM_BEACONS;
 average_noise[1] = data->chain_noise_b / IWL_CAL_NUM_BEACONS;
 average_noise[2] = data->chain_noise_c / IWL_CAL_NUM_BEACONS;

 for (i = 0; i < NUM_RX_CHAINS; i++) {
  if (!(data->disconn_array[i]) &&
     (average_noise[i] <= min_average_noise)) {
   /* This means that chain i is active and has
 * lower noise values so far: */
   min_average_noise = average_noise[i];
   min_average_noise_antenna_i = i;
  }
 }

 IWL_DEBUG_CALIB(priv, "average_noise: a %d b %d c %d\n",
   average_noise[0], average_noise[1],
   average_noise[2]);

 IWL_DEBUG_CALIB(priv, "min_average_noise = %d, antenna %d\n",
   min_average_noise, min_average_noise_antenna_i);

 iwlagn_gain_computation(
  priv, average_noise,
  find_first_chain(priv->nvm_data->valid_rx_ant));

 /* Some power changes may have been made during the calibration.
 * Update and commit the RXON
 */
 iwl_update_chain_flags(priv);

 data->state = IWL_CHAIN_NOISE_DONE;
 iwl_power_update_mode(priv, false);
}

void iwl_reset_run_time_calib(struct iwl_priv *priv)
{
 int i;
 memset(&(priv->sensitivity_data), 0,
        sizeof(struct iwl_sensitivity_data));
 memset(&(priv->chain_noise_data), 0,
        sizeof(struct iwl_chain_noise_data));
 for (i = 0; i < NUM_RX_CHAINS; i++)
  priv->chain_noise_data.delta_gain_code[i] =
    CHAIN_NOISE_DELTA_GAIN_INIT_VAL;

 /* Ask for statistics now, the uCode will send notification
 * periodically after association */
 iwl_send_statistics_request(priv, CMD_ASYNC, true);
}