Merge branch 'akpm'

[linux-2.6/next.git] / drivers / net / wireless / iwlwifi / iwl-agn-rxon.c

/******************************************************************************
 *
 * Copyright(c) 2003 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 * Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include "iwl-dev.h"
#include "iwl-agn.h"
#include "iwl-sta.h"
#include "iwl-core.h"
#include "iwl-agn-calib.h"
#include "iwl-helpers.h"
#include "iwl-trans.h"

static int iwlagn_disable_bss(struct iwl_priv *priv,
                              struct iwl_rxon_context *ctx,
                              struct iwl_rxon_cmd *send)
{
        __le32 old_filter = send->filter_flags;
        int ret;

        send->filter_flags &= ~RXON_FILTER_ASSOC_MSK;
        ret = trans_send_cmd_pdu(&priv->trans, ctx->rxon_cmd,
                                CMD_SYNC, sizeof(*send), send);

        send->filter_flags = old_filter;

        if (ret)
                IWL_ERR(priv, "Error clearing ASSOC_MSK on BSS (%d)\n", ret);

        return ret;
}

static int iwlagn_disable_pan(struct iwl_priv *priv,
                              struct iwl_rxon_context *ctx,
                              struct iwl_rxon_cmd *send)
{
        struct iwl_notification_wait disable_wait;
        __le32 old_filter = send->filter_flags;
        u8 old_dev_type = send->dev_type;
        int ret;

        iwlagn_init_notification_wait(priv, &disable_wait,
                                      REPLY_WIPAN_DEACTIVATION_COMPLETE,
                                      NULL, NULL);

        send->filter_flags &= ~RXON_FILTER_ASSOC_MSK;
        send->dev_type = RXON_DEV_TYPE_P2P;
        ret = trans_send_cmd_pdu(&priv->trans, ctx->rxon_cmd,
                                CMD_SYNC, sizeof(*send), send);

        send->filter_flags = old_filter;
        send->dev_type = old_dev_type;

        if (ret) {
                IWL_ERR(priv, "Error disabling PAN (%d)\n", ret);
                iwlagn_remove_notification(priv, &disable_wait);
        } else {
                ret = iwlagn_wait_notification(priv, &disable_wait, HZ);
                if (ret)
                        IWL_ERR(priv, "Timed out waiting for PAN disable\n");
        }

        return ret;
}

static int iwlagn_disconn_pan(struct iwl_priv *priv,
                              struct iwl_rxon_context *ctx,
                              struct iwl_rxon_cmd *send)
{
        __le32 old_filter = send->filter_flags;
        int ret;

        send->filter_flags &= ~RXON_FILTER_ASSOC_MSK;
        ret = trans_send_cmd_pdu(&priv->trans, ctx->rxon_cmd, CMD_SYNC,
                                sizeof(*send), send);

        send->filter_flags = old_filter;

        return ret;
}

static void iwlagn_update_qos(struct iwl_priv *priv,
                              struct iwl_rxon_context *ctx)
{
        int ret;

        if (!ctx->is_active)
                return;

        ctx->qos_data.def_qos_parm.qos_flags = 0;

        if (ctx->qos_data.qos_active)
                ctx->qos_data.def_qos_parm.qos_flags |=
                        QOS_PARAM_FLG_UPDATE_EDCA_MSK;

        if (ctx->ht.enabled)
                ctx->qos_data.def_qos_parm.qos_flags |= QOS_PARAM_FLG_TGN_MSK;

        IWL_DEBUG_QOS(priv, "send QoS cmd with Qos active=%d FLAGS=0x%X\n",
                      ctx->qos_data.qos_active,
                      ctx->qos_data.def_qos_parm.qos_flags);

        ret = trans_send_cmd_pdu(&priv->trans, ctx->qos_cmd, CMD_SYNC,
                               sizeof(struct iwl_qosparam_cmd),
                               &ctx->qos_data.def_qos_parm);
        if (ret)
                IWL_ERR(priv, "Failed to update QoS\n");
}

static int iwlagn_update_beacon(struct iwl_priv *priv,
                                struct ieee80211_vif *vif)
{
        lockdep_assert_held(&priv->mutex);

        dev_kfree_skb(priv->beacon_skb);
        priv->beacon_skb = ieee80211_beacon_get(priv->hw, vif);
        if (!priv->beacon_skb)
                return -ENOMEM;
        return iwlagn_send_beacon_cmd(priv);
}

static int iwlagn_send_rxon_assoc(struct iwl_priv *priv,
                           struct iwl_rxon_context *ctx)
{
        int ret = 0;
        struct iwl_rxon_assoc_cmd rxon_assoc;
        const struct iwl_rxon_cmd *rxon1 = &ctx->staging;
        const struct iwl_rxon_cmd *rxon2 = &ctx->active;

        if ((rxon1->flags == rxon2->flags) &&
            (rxon1->filter_flags == rxon2->filter_flags) &&
            (rxon1->cck_basic_rates == rxon2->cck_basic_rates) &&
            (rxon1->ofdm_ht_single_stream_basic_rates ==
             rxon2->ofdm_ht_single_stream_basic_rates) &&
            (rxon1->ofdm_ht_dual_stream_basic_rates ==
             rxon2->ofdm_ht_dual_stream_basic_rates) &&
            (rxon1->ofdm_ht_triple_stream_basic_rates ==
             rxon2->ofdm_ht_triple_stream_basic_rates) &&
            (rxon1->acquisition_data == rxon2->acquisition_data) &&
            (rxon1->rx_chain == rxon2->rx_chain) &&
            (rxon1->ofdm_basic_rates == rxon2->ofdm_basic_rates)) {
                IWL_DEBUG_INFO(priv, "Using current RXON_ASSOC.  Not resending.\n");
                return 0;
        }

        rxon_assoc.flags = ctx->staging.flags;
        rxon_assoc.filter_flags = ctx->staging.filter_flags;
        rxon_assoc.ofdm_basic_rates = ctx->staging.ofdm_basic_rates;
        rxon_assoc.cck_basic_rates = ctx->staging.cck_basic_rates;
        rxon_assoc.reserved1 = 0;
        rxon_assoc.reserved2 = 0;
        rxon_assoc.reserved3 = 0;
        rxon_assoc.ofdm_ht_single_stream_basic_rates =
            ctx->staging.ofdm_ht_single_stream_basic_rates;
        rxon_assoc.ofdm_ht_dual_stream_basic_rates =
            ctx->staging.ofdm_ht_dual_stream_basic_rates;
        rxon_assoc.rx_chain_select_flags = ctx->staging.rx_chain;
        rxon_assoc.ofdm_ht_triple_stream_basic_rates =
                 ctx->staging.ofdm_ht_triple_stream_basic_rates;
        rxon_assoc.acquisition_data = ctx->staging.acquisition_data;

        ret = trans_send_cmd_pdu(&priv->trans, ctx->rxon_assoc_cmd,
                                CMD_ASYNC, sizeof(rxon_assoc), &rxon_assoc);
        return ret;
}

static int iwlagn_rxon_disconn(struct iwl_priv *priv,
                               struct iwl_rxon_context *ctx)
{
        int ret;
        struct iwl_rxon_cmd *active = (void *)&ctx->active;

        if (ctx->ctxid == IWL_RXON_CTX_BSS) {
                ret = iwlagn_disable_bss(priv, ctx, &ctx->staging);
        } else {
                ret = iwlagn_disable_pan(priv, ctx, &ctx->staging);
                if (ret)
                        return ret;
                if (ctx->vif) {
                        ret = iwl_send_rxon_timing(priv, ctx);
                        if (ret) {
                                IWL_ERR(priv, "Failed to send timing (%d)!\n", ret);
                                return ret;
                        }
                        ret = iwlagn_disconn_pan(priv, ctx, &ctx->staging);
                }
        }
        if (ret)
                return ret;

        /*
         * Un-assoc RXON clears the station table and WEP
         * keys, so we have to restore those afterwards.
         */
        iwl_clear_ucode_stations(priv, ctx);
        /* update -- might need P2P now */
        iwl_update_bcast_station(priv, ctx);
        iwl_restore_stations(priv, ctx);
        ret = iwl_restore_default_wep_keys(priv, ctx);
        if (ret) {
                IWL_ERR(priv, "Failed to restore WEP keys (%d)\n", ret);
                return ret;
        }

        memcpy(active, &ctx->staging, sizeof(*active));
        return 0;
}

static int iwlagn_rxon_connect(struct iwl_priv *priv,
                               struct iwl_rxon_context *ctx)
{
        int ret;
        struct iwl_rxon_cmd *active = (void *)&ctx->active;

        /* RXON timing must be before associated RXON */
        if (ctx->ctxid == IWL_RXON_CTX_BSS) {
                ret = iwl_send_rxon_timing(priv, ctx);
                if (ret) {
                        IWL_ERR(priv, "Failed to send timing (%d)!\n", ret);
                        return ret;
                }
        }
        /* QoS info may be cleared by previous un-assoc RXON */
        iwlagn_update_qos(priv, ctx);

        /*
         * We'll run into this code path when beaconing is
         * enabled, but then we also need to send the beacon
         * to the device.
         */
        if (ctx->vif && (ctx->vif->type == NL80211_IFTYPE_AP)) {
                ret = iwlagn_update_beacon(priv, ctx->vif);
                if (ret) {
                        IWL_ERR(priv,
                                "Error sending required beacon (%d)!\n",
                                ret);
                        return ret;
                }
        }

        priv->start_calib = 0;
        /*
         * Apply the new configuration.
         *
         * Associated RXON doesn't clear the station table in uCode,
         * so we don't need to restore stations etc. after this.
         */
        ret = trans_send_cmd_pdu(&priv->trans, ctx->rxon_cmd, CMD_SYNC,
                      sizeof(struct iwl_rxon_cmd), &ctx->staging);
        if (ret) {
                IWL_ERR(priv, "Error setting new RXON (%d)\n", ret);
                return ret;
        }
        memcpy(active, &ctx->staging, sizeof(*active));

        iwl_reprogram_ap_sta(priv, ctx);

        /* IBSS beacon needs to be sent after setting assoc */
        if (ctx->vif && (ctx->vif->type == NL80211_IFTYPE_ADHOC))
                if (iwlagn_update_beacon(priv, ctx->vif))
                        IWL_ERR(priv, "Error sending IBSS beacon\n");
        iwl_init_sensitivity(priv);

        /*
         * If we issue a new RXON command which required a tune then
         * we must send a new TXPOWER command or we won't be able to
         * Tx any frames.
         *
         * It's expected we set power here if channel is changing.
         */
        ret = iwl_set_tx_power(priv, priv->tx_power_next, true);
        if (ret) {
                IWL_ERR(priv, "Error sending TX power (%d)\n", ret);
                return ret;
        }

        if ((ctx->vif && ctx->vif->type == NL80211_IFTYPE_STATION) &&
            priv->cfg->ht_params->smps_mode)
                ieee80211_request_smps(ctx->vif,
                                       priv->cfg->ht_params->smps_mode);

        return 0;
}

int iwlagn_set_pan_params(struct iwl_priv *priv)
{
        struct iwl_wipan_params_cmd cmd;
        struct iwl_rxon_context *ctx_bss, *ctx_pan;
        int slot0 = 300, slot1 = 0;
        int ret;

        if (priv->valid_contexts == BIT(IWL_RXON_CTX_BSS))
                return 0;

        BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);

        lockdep_assert_held(&priv->mutex);

        ctx_bss = &priv->contexts[IWL_RXON_CTX_BSS];
        ctx_pan = &priv->contexts[IWL_RXON_CTX_PAN];

        /*
         * If the PAN context is inactive, then we don't need
         * to update the PAN parameters, the last thing we'll
         * have done before it goes inactive is making the PAN
         * parameters be WLAN-only.
         */
        if (!ctx_pan->is_active)
                return 0;

        memset(&cmd, 0, sizeof(cmd));

        /* only 2 slots are currently allowed */
        cmd.num_slots = 2;

        cmd.slots[0].type = 0; /* BSS */
        cmd.slots[1].type = 1; /* PAN */

        if (priv->hw_roc_setup) {
                /* both contexts must be used for this to happen */
                slot1 = IWL_MIN_SLOT_TIME;
                slot0 = 3000;
        } else if (ctx_bss->vif && ctx_pan->vif) {
                int bcnint = ctx_pan->beacon_int;
                int dtim = ctx_pan->vif->bss_conf.dtim_period ?: 1;

                /* should be set, but seems unused?? */
                cmd.flags |= cpu_to_le16(IWL_WIPAN_PARAMS_FLG_SLOTTED_MODE);

                if (ctx_pan->vif->type == NL80211_IFTYPE_AP &&
                    bcnint &&
                    bcnint != ctx_bss->beacon_int) {
                        IWL_ERR(priv,
                                "beacon intervals don't match (%d, %d)\n",
                                ctx_bss->beacon_int, ctx_pan->beacon_int);
                } else
                        bcnint = max_t(int, bcnint,
                                       ctx_bss->beacon_int);
                if (!bcnint)
                        bcnint = DEFAULT_BEACON_INTERVAL;
                slot0 = bcnint / 2;
                slot1 = bcnint - slot0;

                if (test_bit(STATUS_SCAN_HW, &priv->status) ||
                    (!ctx_bss->vif->bss_conf.idle &&
                     !ctx_bss->vif->bss_conf.assoc)) {
                        slot0 = dtim * bcnint * 3 - IWL_MIN_SLOT_TIME;
                        slot1 = IWL_MIN_SLOT_TIME;
                } else if (!ctx_pan->vif->bss_conf.idle &&
                           !ctx_pan->vif->bss_conf.assoc) {
                        slot1 = bcnint * 3 - IWL_MIN_SLOT_TIME;
                        slot0 = IWL_MIN_SLOT_TIME;
                }
        } else if (ctx_pan->vif) {
                slot0 = 0;
                slot1 = max_t(int, 1, ctx_pan->vif->bss_conf.dtim_period) *
                                        ctx_pan->beacon_int;
                slot1 = max_t(int, DEFAULT_BEACON_INTERVAL, slot1);

                if (test_bit(STATUS_SCAN_HW, &priv->status)) {
                        slot0 = slot1 * 3 - IWL_MIN_SLOT_TIME;
                        slot1 = IWL_MIN_SLOT_TIME;
                }
        }

        cmd.slots[0].width = cpu_to_le16(slot0);
        cmd.slots[1].width = cpu_to_le16(slot1);

        ret = trans_send_cmd_pdu(&priv->trans, REPLY_WIPAN_PARAMS, CMD_SYNC,
                        sizeof(cmd), &cmd);
        if (ret)
                IWL_ERR(priv, "Error setting PAN parameters (%d)\n", ret);

        return ret;
}

/**
 * iwlagn_commit_rxon - commit staging_rxon to hardware
 *
 * The RXON command in staging_rxon is committed to the hardware and
 * the active_rxon structure is updated with the new data.  This
 * function correctly transitions out of the RXON_ASSOC_MSK state if
 * a HW tune is required based on the RXON structure changes.
 *
 * The connect/disconnect flow should be as the following:
 *
 * 1. make sure send RXON command with association bit unset if not connect
 *      this should include the channel and the band for the candidate
 *      to be connected to
 * 2. Add Station before RXON association with the AP
 * 3. RXON_timing has to send before RXON for connection
 * 4. full RXON command - associated bit set
 * 5. use RXON_ASSOC command to update any flags changes
 */
int iwlagn_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
{
        /* cast away the const for active_rxon in this function */
        struct iwl_rxon_cmd *active = (void *)&ctx->active;
        bool new_assoc = !!(ctx->staging.filter_flags & RXON_FILTER_ASSOC_MSK);
        int ret;

        lockdep_assert_held(&priv->mutex);

        if (test_bit(STATUS_EXIT_PENDING, &priv->status))
                return -EINVAL;

        if (!iwl_is_alive(priv))
                return -EBUSY;

        /* This function hardcodes a bunch of dual-mode assumptions */
        BUILD_BUG_ON(NUM_IWL_RXON_CTX != 2);

        if (!ctx->is_active)
                return 0;

        /* always get timestamp with Rx frame */
        ctx->staging.flags |= RXON_FLG_TSF2HOST_MSK;

        /*
         * force CTS-to-self frames protection if RTS-CTS is not preferred
         * one aggregation protection method
         */
        if (!(priv->cfg->ht_params &&
              priv->cfg->ht_params->use_rts_for_aggregation))
                ctx->staging.flags |= RXON_FLG_SELF_CTS_EN;

        if ((ctx->vif && ctx->vif->bss_conf.use_short_slot) ||
            !(ctx->staging.flags & RXON_FLG_BAND_24G_MSK))
                ctx->staging.flags |= RXON_FLG_SHORT_SLOT_MSK;
        else
                ctx->staging.flags &= ~RXON_FLG_SHORT_SLOT_MSK;

        iwl_print_rx_config_cmd(priv, ctx);
        ret = iwl_check_rxon_cmd(priv, ctx);
        if (ret) {
                IWL_ERR(priv, "Invalid RXON configuration. Not committing.\n");
                return -EINVAL;
        }

        /*
         * receive commit_rxon request
         * abort any previous channel switch if still in process
         */
        if (test_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status) &&
            (priv->switch_channel != ctx->staging.channel)) {
                IWL_DEBUG_11H(priv, "abort channel switch on %d\n",
                              le16_to_cpu(priv->switch_channel));
                iwl_chswitch_done(priv, false);
        }

        /*
         * If we don't need to send a full RXON, we can use
         * iwl_rxon_assoc_cmd which is used to reconfigure filter
         * and other flags for the current radio configuration.
         */
        if (!iwl_full_rxon_required(priv, ctx)) {
                ret = iwlagn_send_rxon_assoc(priv, ctx);
                if (ret) {
                        IWL_ERR(priv, "Error setting RXON_ASSOC (%d)\n", ret);
                        return ret;
                }

                memcpy(active, &ctx->staging, sizeof(*active));
                /*
                 * We do not commit tx power settings while channel changing,
                 * do it now if after settings changed.
                 */
                iwl_set_tx_power(priv, priv->tx_power_next, false);

                /* make sure we are in the right PS state */
                iwl_power_update_mode(priv, true);

                return 0;
        }

        iwl_set_rxon_hwcrypto(priv, ctx, !iwlagn_mod_params.sw_crypto);

        IWL_DEBUG_INFO(priv,
                       "Going to commit RXON\n"
                       "  * with%s RXON_FILTER_ASSOC_MSK\n"
                       "  * channel = %d\n"
                       "  * bssid = %pM\n",
                       (new_assoc ? "" : "out"),
                       le16_to_cpu(ctx->staging.channel),
                       ctx->staging.bssid_addr);

        /*
         * Always clear associated first, but with the correct config.
         * This is required as for example station addition for the
         * AP station must be done after the BSSID is set to correctly
         * set up filters in the device.
         */
        ret = iwlagn_rxon_disconn(priv, ctx);
        if (ret)
                return ret;

        ret = iwlagn_set_pan_params(priv);
        if (ret)
                return ret;

        if (new_assoc)
                return iwlagn_rxon_connect(priv, ctx);

        return 0;
}

int iwlagn_mac_config(struct ieee80211_hw *hw, u32 changed)
{
        struct iwl_priv *priv = hw->priv;
        struct iwl_rxon_context *ctx;
        struct ieee80211_conf *conf = &hw->conf;
        struct ieee80211_channel *channel = conf->channel;
        const struct iwl_channel_info *ch_info;
        int ret = 0;

        IWL_DEBUG_MAC80211(priv, "changed %#x", changed);

        mutex_lock(&priv->mutex);

        if (unlikely(test_bit(STATUS_SCANNING, &priv->status))) {
                IWL_DEBUG_MAC80211(priv, "leave - scanning\n");
                goto out;
        }

        if (!iwl_is_ready(priv)) {
                IWL_DEBUG_MAC80211(priv, "leave - not ready\n");
                goto out;
        }

        if (changed & (IEEE80211_CONF_CHANGE_SMPS |
                       IEEE80211_CONF_CHANGE_CHANNEL)) {
                /* mac80211 uses static for non-HT which is what we want */
                priv->current_ht_config.smps = conf->smps_mode;

                /*
                 * Recalculate chain counts.
                 *
                 * If monitor mode is enabled then mac80211 will
                 * set up the SM PS mode to OFF if an HT channel is
                 * configured.
                 */
                for_each_context(priv, ctx)
                        iwlagn_set_rxon_chain(priv, ctx);
        }

        if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
                unsigned long flags;

                ch_info = iwl_get_channel_info(priv, channel->band,
                                               channel->hw_value);
                if (!is_channel_valid(ch_info)) {
                        IWL_DEBUG_MAC80211(priv, "leave - invalid channel\n");
                        ret = -EINVAL;
                        goto out;
                }

                spin_lock_irqsave(&priv->lock, flags);

                for_each_context(priv, ctx) {
                        /* Configure HT40 channels */
                        if (ctx->ht.enabled != conf_is_ht(conf))
                                ctx->ht.enabled = conf_is_ht(conf);

                        if (ctx->ht.enabled) {
                                if (conf_is_ht40_minus(conf)) {
                                        ctx->ht.extension_chan_offset =
                                                IEEE80211_HT_PARAM_CHA_SEC_BELOW;
                                        ctx->ht.is_40mhz = true;
                                } else if (conf_is_ht40_plus(conf)) {
                                        ctx->ht.extension_chan_offset =
                                                IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
                                        ctx->ht.is_40mhz = true;
                                } else {
                                        ctx->ht.extension_chan_offset =
                                                IEEE80211_HT_PARAM_CHA_SEC_NONE;
                                        ctx->ht.is_40mhz = false;
                                }
                        } else
                                ctx->ht.is_40mhz = false;

                        /*
                         * Default to no protection. Protection mode will
                         * later be set from BSS config in iwl_ht_conf
                         */
                        ctx->ht.protection = IEEE80211_HT_OP_MODE_PROTECTION_NONE;

                        /* if we are switching from ht to 2.4 clear flags
                         * from any ht related info since 2.4 does not
                         * support ht */
                        if (le16_to_cpu(ctx->staging.channel) !=
                            channel->hw_value)
                                ctx->staging.flags = 0;

                        iwl_set_rxon_channel(priv, channel, ctx);
                        iwl_set_rxon_ht(priv, &priv->current_ht_config);

                        iwl_set_flags_for_band(priv, ctx, channel->band,
                                               ctx->vif);
                }

                spin_unlock_irqrestore(&priv->lock, flags);

                iwl_update_bcast_stations(priv);

                /*
                 * The list of supported rates and rate mask can be different
                 * for each band; since the band may have changed, reset
                 * the rate mask to what mac80211 lists.
                 */
                iwl_set_rate(priv);
        }

        if (changed & (IEEE80211_CONF_CHANGE_PS |
                        IEEE80211_CONF_CHANGE_IDLE)) {
                ret = iwl_power_update_mode(priv, false);
                if (ret)
                        IWL_DEBUG_MAC80211(priv, "Error setting sleep level\n");
        }

        if (changed & IEEE80211_CONF_CHANGE_POWER) {
                IWL_DEBUG_MAC80211(priv, "TX Power old=%d new=%d\n",
                        priv->tx_power_user_lmt, conf->power_level);

                iwl_set_tx_power(priv, conf->power_level, false);
        }

        for_each_context(priv, ctx) {
                if (!memcmp(&ctx->staging, &ctx->active, sizeof(ctx->staging)))
                        continue;
                iwlagn_commit_rxon(priv, ctx);
        }
 out:
        mutex_unlock(&priv->mutex);
        return ret;
}

static void iwlagn_check_needed_chains(struct iwl_priv *priv,
                                       struct iwl_rxon_context *ctx,
                                       struct ieee80211_bss_conf *bss_conf)
{
        struct ieee80211_vif *vif = ctx->vif;
        struct iwl_rxon_context *tmp;
        struct ieee80211_sta *sta;
        struct iwl_ht_config *ht_conf = &priv->current_ht_config;
        struct ieee80211_sta_ht_cap *ht_cap;
        bool need_multiple;

        lockdep_assert_held(&priv->mutex);

        switch (vif->type) {
        case NL80211_IFTYPE_STATION:
                rcu_read_lock();
                sta = ieee80211_find_sta(vif, bss_conf->bssid);
                if (!sta) {
                        /*
                         * If at all, this can only happen through a race
                         * when the AP disconnects us while we're still
                         * setting up the connection, in that case mac80211
                         * will soon tell us about that.
                         */
                        need_multiple = false;
                        rcu_read_unlock();
                        break;
                }

                ht_cap = &sta->ht_cap;

                need_multiple = true;

                /*
                 * If the peer advertises no support for receiving 2 and 3
                 * stream MCS rates, it can't be transmitting them either.
                 */
                if (ht_cap->mcs.rx_mask[1] == 0 &&
                    ht_cap->mcs.rx_mask[2] == 0) {
                        need_multiple = false;
                } else if (!(ht_cap->mcs.tx_params &
                                                IEEE80211_HT_MCS_TX_DEFINED)) {
                        /* If it can't TX MCS at all ... */
                        need_multiple = false;
                } else if (ht_cap->mcs.tx_params &
                                                IEEE80211_HT_MCS_TX_RX_DIFF) {
                        int maxstreams;

                        /*
                         * But if it can receive them, it might still not
                         * be able to transmit them, which is what we need
                         * to check here -- so check the number of streams
                         * it advertises for TX (if different from RX).
                         */

                        maxstreams = (ht_cap->mcs.tx_params &
                                 IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK);
                        maxstreams >>=
                                IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT;
                        maxstreams += 1;

                        if (maxstreams <= 1)
                                need_multiple = false;
                }

                rcu_read_unlock();
                break;
        case NL80211_IFTYPE_ADHOC:
                /* currently */
                need_multiple = false;
                break;
        default:
                /* only AP really */
                need_multiple = true;
                break;
        }

        ctx->ht_need_multiple_chains = need_multiple;

        if (!need_multiple) {
                /* check all contexts */
                for_each_context(priv, tmp) {
                        if (!tmp->vif)
                                continue;
                        if (tmp->ht_need_multiple_chains) {
                                need_multiple = true;
                                break;
                        }
                }
        }

        ht_conf->single_chain_sufficient = !need_multiple;
}

static void iwlagn_chain_noise_reset(struct iwl_priv *priv)
{
        struct iwl_chain_noise_data *data = &priv->chain_noise_data;
        int ret;

        if ((data->state == IWL_CHAIN_NOISE_ALIVE) &&
            iwl_is_any_associated(priv)) {
                struct iwl_calib_chain_noise_reset_cmd cmd;

                /* clear data for chain noise calibration algorithm */
                data->chain_noise_a = 0;
                data->chain_noise_b = 0;
                data->chain_noise_c = 0;
                data->chain_signal_a = 0;
                data->chain_signal_b = 0;
                data->chain_signal_c = 0;
                data->beacon_count = 0;

                memset(&cmd, 0, sizeof(cmd));
                iwl_set_calib_hdr(&cmd.hdr,
                        priv->phy_calib_chain_noise_reset_cmd);
                ret = trans_send_cmd_pdu(&priv->trans,
                                        REPLY_PHY_CALIBRATION_CMD,
                                        CMD_SYNC, sizeof(cmd), &cmd);
                if (ret)
                        IWL_ERR(priv,
                                "Could not send REPLY_PHY_CALIBRATION_CMD\n");
                data->state = IWL_CHAIN_NOISE_ACCUMULATE;
                IWL_DEBUG_CALIB(priv, "Run chain_noise_calibrate\n");
        }
}

void iwlagn_bss_info_changed(struct ieee80211_hw *hw,
                             struct ieee80211_vif *vif,
                             struct ieee80211_bss_conf *bss_conf,
                             u32 changes)
{
        struct iwl_priv *priv = hw->priv;
        struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);
        int ret;
        bool force = false;

        mutex_lock(&priv->mutex);

        if (unlikely(!iwl_is_ready(priv))) {
                IWL_DEBUG_MAC80211(priv, "leave - not ready\n");
                mutex_unlock(&priv->mutex);
                return;
        }

        if (unlikely(!ctx->vif)) {
                IWL_DEBUG_MAC80211(priv, "leave - vif is NULL\n");
                mutex_unlock(&priv->mutex);
                return;
        }

        if (changes & BSS_CHANGED_BEACON_INT)
                force = true;

        if (changes & BSS_CHANGED_QOS) {
                ctx->qos_data.qos_active = bss_conf->qos;
                iwlagn_update_qos(priv, ctx);
        }

        ctx->staging.assoc_id = cpu_to_le16(vif->bss_conf.aid);
        if (vif->bss_conf.use_short_preamble)
                ctx->staging.flags |= RXON_FLG_SHORT_PREAMBLE_MSK;
        else
                ctx->staging.flags &= ~RXON_FLG_SHORT_PREAMBLE_MSK;

        if (changes & BSS_CHANGED_ASSOC) {
                if (bss_conf->assoc) {
                        priv->timestamp = bss_conf->timestamp;
                        ctx->staging.filter_flags |= RXON_FILTER_ASSOC_MSK;
                } else {
                        /*
                         * If we disassociate while there are pending
                         * frames, just wake up the queues and let the
                         * frames "escape" ... This shouldn't really
                         * be happening to start with, but we should
                         * not get stuck in this case either since it
                         * can happen if userspace gets confused.
                         */
                        if (ctx->last_tx_rejected) {
                                ctx->last_tx_rejected = false;
                                iwl_wake_any_queue(priv, ctx);
                        }
                        ctx->staging.filter_flags &= ~RXON_FILTER_ASSOC_MSK;

                        if (ctx->ctxid == IWL_RXON_CTX_BSS)
                                priv->have_rekey_data = false;
                }

                iwlagn_bt_coex_rssi_monitor(priv);
        }

        if (ctx->ht.enabled) {
                ctx->ht.protection = bss_conf->ht_operation_mode &
                                        IEEE80211_HT_OP_MODE_PROTECTION;
                ctx->ht.non_gf_sta_present = !!(bss_conf->ht_operation_mode &
                                        IEEE80211_HT_OP_MODE_NON_GF_STA_PRSNT);
                iwlagn_check_needed_chains(priv, ctx, bss_conf);
                iwl_set_rxon_ht(priv, &priv->current_ht_config);
        }

        iwlagn_set_rxon_chain(priv, ctx);

        if (bss_conf->use_cts_prot && (priv->band != IEEE80211_BAND_5GHZ))
                ctx->staging.flags |= RXON_FLG_TGG_PROTECT_MSK;
        else
                ctx->staging.flags &= ~RXON_FLG_TGG_PROTECT_MSK;

        if (bss_conf->use_cts_prot)
                ctx->staging.flags |= RXON_FLG_SELF_CTS_EN;
        else
                ctx->staging.flags &= ~RXON_FLG_SELF_CTS_EN;

        memcpy(ctx->staging.bssid_addr, bss_conf->bssid, ETH_ALEN);

        if (vif->type == NL80211_IFTYPE_AP ||
            vif->type == NL80211_IFTYPE_ADHOC) {
                if (vif->bss_conf.enable_beacon) {
                        ctx->staging.filter_flags |= RXON_FILTER_ASSOC_MSK;
                        priv->beacon_ctx = ctx;
                } else {
                        ctx->staging.filter_flags &= ~RXON_FILTER_ASSOC_MSK;
                        priv->beacon_ctx = NULL;
                }
        }

        if (force || memcmp(&ctx->staging, &ctx->active, sizeof(ctx->staging)))
                iwlagn_commit_rxon(priv, ctx);

        if (changes & BSS_CHANGED_ASSOC && bss_conf->assoc) {
                /*
                 * The chain noise calibration will enable PM upon
                 * completion. If calibration has already been run
                 * then we need to enable power management here.
                 */
                if (priv->chain_noise_data.state == IWL_CHAIN_NOISE_DONE)
                        iwl_power_update_mode(priv, false);

                /* Enable RX differential gain and sensitivity calibrations */
                if (!priv->disable_chain_noise_cal)
                        iwlagn_chain_noise_reset(priv);
                priv->start_calib = 1;
        }

        if (changes & BSS_CHANGED_IBSS) {
                ret = iwlagn_manage_ibss_station(priv, vif,
                                                 bss_conf->ibss_joined);
                if (ret)
                        IWL_ERR(priv, "failed to %s IBSS station %pM\n",
                                bss_conf->ibss_joined ? "add" : "remove",
                                bss_conf->bssid);
        }

        if (changes & BSS_CHANGED_BEACON && vif->type == NL80211_IFTYPE_ADHOC &&
            priv->beacon_ctx) {
                if (iwlagn_update_beacon(priv, vif))
                        IWL_ERR(priv, "Error sending IBSS beacon\n");
        }

        mutex_unlock(&priv->mutex);
}

void iwlagn_post_scan(struct iwl_priv *priv)
{
        struct iwl_rxon_context *ctx;

        /*
         * We do not commit power settings while scan is pending,
         * do it now if the settings changed.
         */
        iwl_power_set_mode(priv, &priv->power_data.sleep_cmd_next, false);
        iwl_set_tx_power(priv, priv->tx_power_next, false);

        /*
         * Since setting the RXON may have been deferred while
         * performing the scan, fire one off if needed
         */
        for_each_context(priv, ctx)
                if (memcmp(&ctx->staging, &ctx->active, sizeof(ctx->staging)))
                        iwlagn_commit_rxon(priv, ctx);

        iwlagn_set_pan_params(priv);
}