tx.c

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/******************************************************************************
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2012 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.GPL.
 *
 * Contact Information:
 *  Intel Linux Wireless <[email protected]>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/ieee80211.h>
#include "iwl-io.h"
#include "iwl-trans.h"
#include "iwl-agn-hw.h"
#include "dev.h"
#include "agn.h"

static const u8 tid_to_ac[] = {
    IEEE80211_AC_BE,
    IEEE80211_AC_BK,
    IEEE80211_AC_BK,
    IEEE80211_AC_BE,
    IEEE80211_AC_VI,
    IEEE80211_AC_VI,
    IEEE80211_AC_VO,
    IEEE80211_AC_VO,
};

static void iwlagn_tx_cmd_protection(struct iwl_priv *priv,
                     struct ieee80211_tx_info *info,
                     __le16 fc, __le32 *tx_flags)
{
    if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS ||
        info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT ||
        info->flags & IEEE80211_TX_CTL_AMPDU)
        *tx_flags |= TX_CMD_FLG_PROT_REQUIRE_MSK;
}

/*
 * handle build REPLY_TX command notification.
 */
static void iwlagn_tx_cmd_build_basic(struct iwl_priv *priv,
                      struct sk_buff *skb,
                      struct iwl_tx_cmd *tx_cmd,
                      struct ieee80211_tx_info *info,
                      struct ieee80211_hdr *hdr, u8 sta_id)
{
    __le16 fc = hdr->frame_control;
    __le32 tx_flags = tx_cmd->tx_flags;

    tx_cmd->stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;

    if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
        tx_flags |= TX_CMD_FLG_ACK_MSK;
    else
        tx_flags &= ~TX_CMD_FLG_ACK_MSK;

    if (ieee80211_is_probe_resp(fc))
        tx_flags |= TX_CMD_FLG_TSF_MSK;
    else if (ieee80211_is_back_req(fc))
        tx_flags |= TX_CMD_FLG_ACK_MSK | TX_CMD_FLG_IMM_BA_RSP_MASK;
    else if (info->band == IEEE80211_BAND_2GHZ &&
         priv->cfg->bt_params &&
         priv->cfg->bt_params->advanced_bt_coexist &&
         (ieee80211_is_auth(fc) || ieee80211_is_assoc_req(fc) ||
         ieee80211_is_reassoc_req(fc) ||
         skb->protocol == cpu_to_be16(ETH_P_PAE)))
        tx_flags |= TX_CMD_FLG_IGNORE_BT;


    tx_cmd->sta_id = sta_id;
    if (ieee80211_has_morefrags(fc))
        tx_flags |= TX_CMD_FLG_MORE_FRAG_MSK;

    if (ieee80211_is_data_qos(fc)) {
        u8 *qc = ieee80211_get_qos_ctl(hdr);
        tx_cmd->tid_tspec = qc[0] & 0xf;
        tx_flags &= ~TX_CMD_FLG_SEQ_CTL_MSK;
    } else {
        tx_cmd->tid_tspec = IWL_TID_NON_QOS;
        if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
            tx_flags |= TX_CMD_FLG_SEQ_CTL_MSK;
        else
            tx_flags &= ~TX_CMD_FLG_SEQ_CTL_MSK;
    }

    iwlagn_tx_cmd_protection(priv, info, fc, &tx_flags);

    tx_flags &= ~(TX_CMD_FLG_ANT_SEL_MSK);
    if (ieee80211_is_mgmt(fc)) {
        if (ieee80211_is_assoc_req(fc) || ieee80211_is_reassoc_req(fc))
            tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(3);
        else
            tx_cmd->timeout.pm_frame_timeout = cpu_to_le16(2);
    } else {
        tx_cmd->timeout.pm_frame_timeout = 0;
    }

    tx_cmd->driver_txop = 0;
    tx_cmd->tx_flags = tx_flags;
    tx_cmd->next_frame_len = 0;
}

static void iwlagn_tx_cmd_build_rate(struct iwl_priv *priv,
                     struct iwl_tx_cmd *tx_cmd,
                     struct ieee80211_tx_info *info,
                     struct ieee80211_sta *sta,
                     __le16 fc)
{
    u32 rate_flags;
    int rate_idx;
    u8 rts_retry_limit;
    u8 data_retry_limit;
    u8 rate_plcp;

    if (priv->wowlan) {
        rts_retry_limit = IWLAGN_LOW_RETRY_LIMIT;
        data_retry_limit = IWLAGN_LOW_RETRY_LIMIT;
    } else {
        /* Set retry limit on RTS packets */
        rts_retry_limit = IWLAGN_RTS_DFAULT_RETRY_LIMIT;

        /* Set retry limit on DATA packets and Probe Responses*/
        if (ieee80211_is_probe_resp(fc)) {
            data_retry_limit = IWLAGN_MGMT_DFAULT_RETRY_LIMIT;
            rts_retry_limit =
                min(data_retry_limit, rts_retry_limit);
        } else if (ieee80211_is_back_req(fc))
            data_retry_limit = IWLAGN_BAR_DFAULT_RETRY_LIMIT;
        else
            data_retry_limit = IWLAGN_DEFAULT_TX_RETRY;
    }

    tx_cmd->data_retry_limit = data_retry_limit;
    tx_cmd->rts_retry_limit = rts_retry_limit;

    /* DATA packets will use the uCode station table for rate/antenna
     * selection */
    if (ieee80211_is_data(fc)) {
        tx_cmd->initial_rate_index = 0;
        tx_cmd->tx_flags |= TX_CMD_FLG_STA_RATE_MSK;
#ifdef CONFIG_IWLWIFI_DEVICE_TESTMODE
        if (priv->tm_fixed_rate) {
            /*
             * rate overwrite by testmode
             * we not only send lq command to change rate
             * we also re-enforce per data pkt base.
             */
            tx_cmd->tx_flags &= ~TX_CMD_FLG_STA_RATE_MSK;
            memcpy(&tx_cmd->rate_n_flags, &priv->tm_fixed_rate,
                   sizeof(tx_cmd->rate_n_flags));
        }
#endif
        return;
    } else if (ieee80211_is_back_req(fc))
        tx_cmd->tx_flags |= TX_CMD_FLG_STA_RATE_MSK;

    rate_idx = info->control.rates[0].idx;
    if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS ||
            (rate_idx < 0) || (rate_idx > IWL_RATE_COUNT_LEGACY))
        rate_idx = rate_lowest_index(
                &priv->eeprom_data->bands[info->band], sta);
    /* For 5 GHZ band, remap mac80211 rate indices into driver indices */
    if (info->band == IEEE80211_BAND_5GHZ)
        rate_idx += IWL_FIRST_OFDM_RATE;
    /* Get PLCP rate for tx_cmd->rate_n_flags */
    rate_plcp = iwl_rates[rate_idx].plcp;
    /* Zero out flags for this packet */
    rate_flags = 0;

    /* Set CCK flag as needed */
    if ((rate_idx >= IWL_FIRST_CCK_RATE) && (rate_idx <= IWL_LAST_CCK_RATE))
        rate_flags |= RATE_MCS_CCK_MSK;

    /* Set up antennas */
     if (priv->cfg->bt_params &&
         priv->cfg->bt_params->advanced_bt_coexist &&
         priv->bt_full_concurrent) {
        /* operated as 1x1 in full concurrency mode */
        priv->mgmt_tx_ant = iwl_toggle_tx_ant(priv, priv->mgmt_tx_ant,
                first_antenna(priv->eeprom_data->valid_tx_ant));
    } else
        priv->mgmt_tx_ant = iwl_toggle_tx_ant(
                    priv, priv->mgmt_tx_ant,
                    priv->eeprom_data->valid_tx_ant);
    rate_flags |= iwl_ant_idx_to_flags(priv->mgmt_tx_ant);

    /* Set the rate in the TX cmd */
    tx_cmd->rate_n_flags = iwl_hw_set_rate_n_flags(rate_plcp, rate_flags);
}

static void iwlagn_tx_cmd_build_hwcrypto(struct iwl_priv *priv,
                     struct ieee80211_tx_info *info,
                     struct iwl_tx_cmd *tx_cmd,
                     struct sk_buff *skb_frag)
{
    struct ieee80211_key_conf *keyconf = info->control.hw_key;

    switch (keyconf->cipher) {
    case WLAN_CIPHER_SUITE_CCMP:
        tx_cmd->sec_ctl = TX_CMD_SEC_CCM;
        memcpy(tx_cmd->key, keyconf->key, keyconf->keylen);
        if (info->flags & IEEE80211_TX_CTL_AMPDU)
            tx_cmd->tx_flags |= TX_CMD_FLG_AGG_CCMP_MSK;
        IWL_DEBUG_TX(priv, "tx_cmd with AES hwcrypto\n");
        break;

    case WLAN_CIPHER_SUITE_TKIP:
        tx_cmd->sec_ctl = TX_CMD_SEC_TKIP;
        ieee80211_get_tkip_p2k(keyconf, skb_frag, tx_cmd->key);
        IWL_DEBUG_TX(priv, "tx_cmd with tkip hwcrypto\n");
        break;

    case WLAN_CIPHER_SUITE_WEP104:
        tx_cmd->sec_ctl |= TX_CMD_SEC_KEY128;
        /* fall through */
    case WLAN_CIPHER_SUITE_WEP40:
        tx_cmd->sec_ctl |= (TX_CMD_SEC_WEP |
            (keyconf->keyidx & TX_CMD_SEC_MSK) << TX_CMD_SEC_SHIFT);

        memcpy(&tx_cmd->key[3], keyconf->key, keyconf->keylen);

        IWL_DEBUG_TX(priv, "Configuring packet for WEP encryption "
                 "with key %d\n", keyconf->keyidx);
        break;

    default:
        IWL_ERR(priv, "Unknown encode cipher %x\n", keyconf->cipher);
        break;
    }
}

static int iwl_sta_id_or_broadcast(struct iwl_rxon_context *context,
                   struct ieee80211_sta *sta)
{
    int sta_id;

    if (!sta)
        return context->bcast_sta_id;

    sta_id = iwl_sta_id(sta);

    /*
     * mac80211 should not be passing a partially
     * initialised station!
     */
    WARN_ON(sta_id == IWL_INVALID_STATION);

    return sta_id;
}

/*
 * start REPLY_TX command process
 */
int iwlagn_tx_skb(struct iwl_priv *priv,
          struct ieee80211_sta *sta,
          struct sk_buff *skb)
{
    struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
    struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
    struct iwl_station_priv *sta_priv = NULL;
    struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
    struct iwl_device_cmd *dev_cmd;
    struct iwl_tx_cmd *tx_cmd;
    __le16 fc;
    u8 hdr_len;
    u16 len, seq_number = 0;
    u8 sta_id, tid = IWL_MAX_TID_COUNT;
    bool is_agg = false;
    int txq_id;

    if (info->control.vif)
        ctx = iwl_rxon_ctx_from_vif(info->control.vif);

    if (iwl_is_rfkill(priv)) {
        IWL_DEBUG_DROP(priv, "Dropping - RF KILL\n");
        goto drop_unlock_priv;
    }

    fc = hdr->frame_control;

#ifdef CONFIG_IWLWIFI_DEBUG
    if (ieee80211_is_auth(fc))
        IWL_DEBUG_TX(priv, "Sending AUTH frame\n");
    else if (ieee80211_is_assoc_req(fc))
        IWL_DEBUG_TX(priv, "Sending ASSOC frame\n");
    else if (ieee80211_is_reassoc_req(fc))
        IWL_DEBUG_TX(priv, "Sending REASSOC frame\n");
#endif

    if (unlikely(ieee80211_is_probe_resp(fc))) {
        struct iwl_wipan_noa_data *noa_data =
            rcu_dereference(priv->noa_data);

        if (noa_data &&
            pskb_expand_head(skb, 0, noa_data->length,
                     GFP_ATOMIC) == 0) {
            memcpy(skb_put(skb, noa_data->length),
                   noa_data->data, noa_data->length);
            hdr = (struct ieee80211_hdr *)skb->data;
        }
    }

    hdr_len = ieee80211_hdrlen(fc);

    /* For management frames use broadcast id to do not break aggregation */
    if (!ieee80211_is_data(fc))
        sta_id = ctx->bcast_sta_id;
    else {
        /* Find index into station table for destination station */
        sta_id = iwl_sta_id_or_broadcast(ctx, sta);
        if (sta_id == IWL_INVALID_STATION) {
            IWL_DEBUG_DROP(priv, "Dropping - INVALID STATION: %pM\n",
                       hdr->addr1);
            goto drop_unlock_priv;
        }
    }

    IWL_DEBUG_TX(priv, "station Id %d\n", sta_id);

    if (sta)
        sta_priv = (void *)sta->drv_priv;

    if (sta_priv && sta_priv->asleep &&
        (info->flags & IEEE80211_TX_CTL_NO_PS_BUFFER)) {
        /*
         * This sends an asynchronous command to the device,
         * but we can rely on it being processed before the
         * next frame is processed -- and the next frame to
         * this station is the one that will consume this
         * counter.
         * For now set the counter to just 1 since we do not
         * support uAPSD yet.
         *
         * FIXME: If we get two non-bufferable frames one
         * after the other, we might only send out one of
         * them because this is racy.
         */
        iwl_sta_modify_sleep_tx_count(priv, sta_id, 1);
    }

    if (info->flags & IEEE80211_TX_CTL_AMPDU)
        is_agg = true;

    dev_cmd = iwl_trans_alloc_tx_cmd(priv->trans);

    if (unlikely(!dev_cmd))
        goto drop_unlock_priv;

    memset(dev_cmd, 0, sizeof(*dev_cmd));
    tx_cmd = (struct iwl_tx_cmd *) dev_cmd->payload;

    /* Total # bytes to be transmitted */
    len = (u16)skb->len;
    tx_cmd->len = cpu_to_le16(len);

    if (info->control.hw_key)
        iwlagn_tx_cmd_build_hwcrypto(priv, info, tx_cmd, skb);

    /* TODO need this for burst mode later on */
    iwlagn_tx_cmd_build_basic(priv, skb, tx_cmd, info, hdr, sta_id);

    iwlagn_tx_cmd_build_rate(priv, tx_cmd, info, sta, fc);

    memset(&info->status, 0, sizeof(info->status));

    info->driver_data[0] = ctx;
    info->driver_data[1] = dev_cmd;
    /* From now on, we cannot access info->control */

    spin_lock(&priv->sta_lock);

    if (ieee80211_is_data_qos(fc) && !ieee80211_is_qos_nullfunc(fc)) {
        u8 *qc = NULL;
        struct iwl_tid_data *tid_data;
        qc = ieee80211_get_qos_ctl(hdr);
        tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
        if (WARN_ON_ONCE(tid >= IWL_MAX_TID_COUNT))
            goto drop_unlock_sta;
        tid_data = &priv->tid_data[sta_id][tid];

        /* aggregation is on for this <sta,tid> */
        if (info->flags & IEEE80211_TX_CTL_AMPDU &&
            tid_data->agg.state != IWL_AGG_ON) {
            IWL_ERR(priv, "TX_CTL_AMPDU while not in AGG:"
                " Tx flags = 0x%08x, agg.state = %d",
                info->flags, tid_data->agg.state);
            IWL_ERR(priv, "sta_id = %d, tid = %d seq_num = %d",
                sta_id, tid, SEQ_TO_SN(tid_data->seq_number));
            goto drop_unlock_sta;
        }

        /* We can receive packets from the stack in IWL_AGG_{ON,OFF}
         * only. Check this here.
         */
        if (WARN_ONCE(tid_data->agg.state != IWL_AGG_ON &&
                  tid_data->agg.state != IWL_AGG_OFF,
            "Tx while agg.state = %d", tid_data->agg.state))
            goto drop_unlock_sta;

        seq_number = tid_data->seq_number;
        seq_number &= IEEE80211_SCTL_SEQ;
        hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
        hdr->seq_ctrl |= cpu_to_le16(seq_number);
        seq_number += 0x10;
    }

    /* Copy MAC header from skb into command buffer */
    memcpy(tx_cmd->hdr, hdr, hdr_len);

    if (is_agg)
        txq_id = priv->tid_data[sta_id][tid].agg.txq_id;
    else if (info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM) {
        /*
         * Send this frame after DTIM -- there's a special queue
         * reserved for this for contexts that support AP mode.
         */
        txq_id = ctx->mcast_queue;

        /*
         * The microcode will clear the more data
         * bit in the last frame it transmits.
         */
        hdr->frame_control |=
            cpu_to_le16(IEEE80211_FCTL_MOREDATA);
    } else if (info->flags & IEEE80211_TX_CTL_TX_OFFCHAN)
        txq_id = IWL_AUX_QUEUE;
    else
        txq_id = ctx->ac_to_queue[skb_get_queue_mapping(skb)];

    WARN_ON_ONCE(!is_agg && txq_id != info->hw_queue);
    WARN_ON_ONCE(is_agg &&
             priv->queue_to_mac80211[txq_id] != info->hw_queue);

    if (iwl_trans_tx(priv->trans, skb, dev_cmd, txq_id))
        goto drop_unlock_sta;

    if (ieee80211_is_data_qos(fc) && !ieee80211_is_qos_nullfunc(fc) &&
        !ieee80211_has_morefrags(fc))
        priv->tid_data[sta_id][tid].seq_number = seq_number;

    spin_unlock(&priv->sta_lock);

    /*
     * Avoid atomic ops if it isn't an associated client.
     * Also, if this is a packet for aggregation, don't
     * increase the counter because the ucode will stop
     * aggregation queues when their respective station
     * goes to sleep.
     */
    if (sta_priv && sta_priv->client && !is_agg)
        atomic_inc(&sta_priv->pending_frames);

    if (info->flags & IEEE80211_TX_CTL_TX_OFFCHAN)
        iwl_scan_offchannel_skb(priv);

    return 0;

drop_unlock_sta:
    if (dev_cmd)
        iwl_trans_free_tx_cmd(priv->trans, dev_cmd);
    spin_unlock(&priv->sta_lock);
drop_unlock_priv:
    return -1;
}

static int iwlagn_alloc_agg_txq(struct iwl_priv *priv, int mq)
{
    int q;

    for (q = IWLAGN_FIRST_AMPDU_QUEUE;
         q < priv->cfg->base_params->num_of_queues; q++) {
        if (!test_and_set_bit(q, priv->agg_q_alloc)) {
            priv->queue_to_mac80211[q] = mq;
            return q;
        }
    }

    return -ENOSPC;
}

static void iwlagn_dealloc_agg_txq(struct iwl_priv *priv, int q)
{
    clear_bit(q, priv->agg_q_alloc);
    priv->queue_to_mac80211[q] = IWL_INVALID_MAC80211_QUEUE;
}

int iwlagn_tx_agg_stop(struct iwl_priv *priv, struct ieee80211_vif *vif,
            struct ieee80211_sta *sta, u16 tid)
{
    struct iwl_tid_data *tid_data;
    int sta_id, txq_id;
    enum iwl_agg_state agg_state;

    sta_id = iwl_sta_id(sta);

    if (sta_id == IWL_INVALID_STATION) {
        IWL_ERR(priv, "Invalid station for AGG tid %d\n", tid);
        return -ENXIO;
    }

    spin_lock_bh(&priv->sta_lock);

    tid_data = &priv->tid_data[sta_id][tid];
    txq_id = priv->tid_data[sta_id][tid].agg.txq_id;

    switch (priv->tid_data[sta_id][tid].agg.state) {
    case IWL_EMPTYING_HW_QUEUE_ADDBA:
        /*
        * This can happen if the peer stops aggregation
        * again before we've had a chance to drain the
        * queue we selected previously, i.e. before the
        * session was really started completely.
        */
        IWL_DEBUG_HT(priv, "AGG stop before setup done\n");
        goto turn_off;
    case IWL_AGG_STARTING:
        /*
         * This can happen when the session is stopped before
         * we receive ADDBA response
         */
        IWL_DEBUG_HT(priv, "AGG stop before AGG became operational\n");
        goto turn_off;
    case IWL_AGG_ON:
        break;
    default:
        IWL_WARN(priv, "Stopping AGG while state not ON "
             "or starting for %d on %d (%d)\n", sta_id, tid,
             priv->tid_data[sta_id][tid].agg.state);
        spin_unlock_bh(&priv->sta_lock);
        return 0;
    }

    tid_data->agg.ssn = SEQ_TO_SN(tid_data->seq_number);

    /* There are still packets for this RA / TID in the HW */
    if (!test_bit(txq_id, priv->agg_q_alloc)) {
        IWL_DEBUG_TX_QUEUES(priv,
            "stopping AGG on STA/TID %d/%d but hwq %d not used\n",
            sta_id, tid, txq_id);
    } else if (tid_data->agg.ssn != tid_data->next_reclaimed) {
        IWL_DEBUG_TX_QUEUES(priv, "Can't proceed: ssn %d, "
                    "next_recl = %d\n",
                    tid_data->agg.ssn,
                    tid_data->next_reclaimed);
        priv->tid_data[sta_id][tid].agg.state =
            IWL_EMPTYING_HW_QUEUE_DELBA;
        spin_unlock_bh(&priv->sta_lock);
        return 0;
    }

    IWL_DEBUG_TX_QUEUES(priv, "Can proceed: ssn = next_recl = %d\n",
                tid_data->agg.ssn);
turn_off:
    agg_state = priv->tid_data[sta_id][tid].agg.state;
    priv->tid_data[sta_id][tid].agg.state = IWL_AGG_OFF;

    spin_unlock_bh(&priv->sta_lock);

    if (test_bit(txq_id, priv->agg_q_alloc)) {
        /*
         * If the transport didn't know that we wanted to start
         * agreggation, don't tell it that we want to stop them.
         * This can happen when we don't get the addBA response on
         * time, or we hadn't time to drain the AC queues.
         */
        if (agg_state == IWL_AGG_ON)
            iwl_trans_txq_disable(priv->trans, txq_id);
        else
            IWL_DEBUG_TX_QUEUES(priv, "Don't disable tx agg: %d\n",
                        agg_state);
        iwlagn_dealloc_agg_txq(priv, txq_id);
    }

    ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);

    return 0;
}

int iwlagn_tx_agg_start(struct iwl_priv *priv, struct ieee80211_vif *vif,
            struct ieee80211_sta *sta, u16 tid, u16 *ssn)
{
    struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);
    struct iwl_tid_data *tid_data;
    int sta_id, txq_id, ret;

    IWL_DEBUG_HT(priv, "TX AGG request on ra = %pM tid = %d\n",
             sta->addr, tid);

    sta_id = iwl_sta_id(sta);
    if (sta_id == IWL_INVALID_STATION) {
        IWL_ERR(priv, "Start AGG on invalid station\n");
        return -ENXIO;
    }
    if (unlikely(tid >= IWL_MAX_TID_COUNT))
        return -EINVAL;

    if (priv->tid_data[sta_id][tid].agg.state != IWL_AGG_OFF) {
        IWL_ERR(priv, "Start AGG when state is not IWL_AGG_OFF !\n");
        return -ENXIO;
    }

    txq_id = iwlagn_alloc_agg_txq(priv, ctx->ac_to_queue[tid_to_ac[tid]]);
    if (txq_id < 0) {
        IWL_DEBUG_TX_QUEUES(priv,
            "No free aggregation queue for %pM/%d\n",
            sta->addr, tid);
        return txq_id;
    }

    ret = iwl_sta_tx_modify_enable_tid(priv, sta_id, tid);
    if (ret)
        return ret;

    spin_lock_bh(&priv->sta_lock);
    tid_data = &priv->tid_data[sta_id][tid];
    tid_data->agg.ssn = SEQ_TO_SN(tid_data->seq_number);
    tid_data->agg.txq_id = txq_id;

    *ssn = tid_data->agg.ssn;

    if (*ssn == tid_data->next_reclaimed) {
        IWL_DEBUG_TX_QUEUES(priv, "Can proceed: ssn = next_recl = %d\n",
                    tid_data->agg.ssn);
        tid_data->agg.state = IWL_AGG_STARTING;
        ieee80211_start_tx_ba_cb_irqsafe(vif, sta->addr, tid);
    } else {
        IWL_DEBUG_TX_QUEUES(priv, "Can't proceed: ssn %d, "
                    "next_reclaimed = %d\n",
                    tid_data->agg.ssn,
                    tid_data->next_reclaimed);
        tid_data->agg.state = IWL_EMPTYING_HW_QUEUE_ADDBA;
    }
    spin_unlock_bh(&priv->sta_lock);

    return ret;
}

int iwlagn_tx_agg_oper(struct iwl_priv *priv, struct ieee80211_vif *vif,
            struct ieee80211_sta *sta, u16 tid, u8 buf_size)
{
    struct iwl_station_priv *sta_priv = (void *) sta->drv_priv;
    struct iwl_rxon_context *ctx = iwl_rxon_ctx_from_vif(vif);
    int q, fifo;
    u16 ssn;

    buf_size = min_t(int, buf_size, LINK_QUAL_AGG_FRAME_LIMIT_DEF);

    spin_lock_bh(&priv->sta_lock);
    ssn = priv->tid_data[sta_priv->sta_id][tid].agg.ssn;
    q = priv->tid_data[sta_priv->sta_id][tid].agg.txq_id;
    priv->tid_data[sta_priv->sta_id][tid].agg.state = IWL_AGG_ON;
    spin_unlock_bh(&priv->sta_lock);

    fifo = ctx->ac_to_fifo[tid_to_ac[tid]];

    iwl_trans_txq_enable(priv->trans, q, fifo, sta_priv->sta_id, tid,
                 buf_size, ssn);

    /*
     * If the limit is 0, then it wasn't initialised yet,
     * use the default. We can do that since we take the
     * minimum below, and we don't want to go above our
     * default due to hardware restrictions.
     */
    if (sta_priv->max_agg_bufsize == 0)
        sta_priv->max_agg_bufsize =
            LINK_QUAL_AGG_FRAME_LIMIT_DEF;

    /*
     * Even though in theory the peer could have different
     * aggregation reorder buffer sizes for different sessions,
     * our ucode doesn't allow for that and has a global limit
     * for each station. Therefore, use the minimum of all the
     * aggregation sessions and our default value.
     */
    sta_priv->max_agg_bufsize =
        min(sta_priv->max_agg_bufsize, buf_size);

    if (priv->hw_params.use_rts_for_aggregation) {
        /*
         * switch to RTS/CTS if it is the prefer protection
         * method for HT traffic
         */

        sta_priv->lq_sta.lq.general_params.flags |=
            LINK_QUAL_FLAGS_SET_STA_TLC_RTS_MSK;
    }
    priv->agg_tids_count++;
    IWL_DEBUG_HT(priv, "priv->agg_tids_count = %u\n",
             priv->agg_tids_count);

    sta_priv->lq_sta.lq.agg_params.agg_frame_cnt_limit =
        sta_priv->max_agg_bufsize;

    IWL_DEBUG_HT(priv, "Tx aggregation enabled on ra = %pM tid = %d\n",
         sta->addr, tid);

    return iwl_send_lq_cmd(priv, ctx,
            &sta_priv->lq_sta.lq, CMD_ASYNC, false);
}

static void iwlagn_check_ratid_empty(struct iwl_priv *priv, int sta_id, u8 tid)
{
    struct iwl_tid_data *tid_data = &priv->tid_data[sta_id][tid];
    enum iwl_rxon_context_id ctx;
    struct ieee80211_vif *vif;
    u8 *addr;

    lockdep_assert_held(&priv->sta_lock);

    addr = priv->stations[sta_id].sta.sta.addr;
    ctx = priv->stations[sta_id].ctxid;
    vif = priv->contexts[ctx].vif;

    switch (priv->tid_data[sta_id][tid].agg.state) {
    case IWL_EMPTYING_HW_QUEUE_DELBA:
        /* There are no packets for this RA / TID in the HW any more */
        if (tid_data->agg.ssn == tid_data->next_reclaimed) {
            IWL_DEBUG_TX_QUEUES(priv,
                "Can continue DELBA flow ssn = next_recl ="
                " %d", tid_data->next_reclaimed);
            iwl_trans_txq_disable(priv->trans,
                          tid_data->agg.txq_id);
            iwlagn_dealloc_agg_txq(priv, tid_data->agg.txq_id);
            tid_data->agg.state = IWL_AGG_OFF;
            ieee80211_stop_tx_ba_cb_irqsafe(vif, addr, tid);
        }
        break;
    case IWL_EMPTYING_HW_QUEUE_ADDBA:
        /* There are no packets for this RA / TID in the HW any more */
        if (tid_data->agg.ssn == tid_data->next_reclaimed) {
            IWL_DEBUG_TX_QUEUES(priv,
                "Can continue ADDBA flow ssn = next_recl ="
                " %d", tid_data->next_reclaimed);
            tid_data->agg.state = IWL_AGG_STARTING;
            ieee80211_start_tx_ba_cb_irqsafe(vif, addr, tid);
        }
        break;
    default:
        break;
    }
}

static void iwlagn_non_agg_tx_status(struct iwl_priv *priv,
                     struct iwl_rxon_context *ctx,
                     const u8 *addr1)
{
    struct ieee80211_sta *sta;
    struct iwl_station_priv *sta_priv;

    rcu_read_lock();
    sta = ieee80211_find_sta(ctx->vif, addr1);
    if (sta) {
        sta_priv = (void *)sta->drv_priv;
        /* avoid atomic ops if this isn't a client */
        if (sta_priv->client &&
            atomic_dec_return(&sta_priv->pending_frames) == 0)
            ieee80211_sta_block_awake(priv->hw, sta, false);
    }
    rcu_read_unlock();
}

static void iwlagn_hwrate_to_tx_control(struct iwl_priv *priv, u32 rate_n_flags,
                  struct ieee80211_tx_info *info)
{
    struct ieee80211_tx_rate *r = &info->status.rates[0];

    info->status.antenna =
        ((rate_n_flags & RATE_MCS_ANT_ABC_MSK) >> RATE_MCS_ANT_POS);
    if (rate_n_flags & RATE_MCS_HT_MSK)
        r->flags |= IEEE80211_TX_RC_MCS;
    if (rate_n_flags & RATE_MCS_GF_MSK)
        r->flags |= IEEE80211_TX_RC_GREEN_FIELD;
    if (rate_n_flags & RATE_MCS_HT40_MSK)
        r->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
    if (rate_n_flags & RATE_MCS_DUP_MSK)
        r->flags |= IEEE80211_TX_RC_DUP_DATA;
    if (rate_n_flags & RATE_MCS_SGI_MSK)
        r->flags |= IEEE80211_TX_RC_SHORT_GI;
    r->idx = iwlagn_hwrate_to_mac80211_idx(rate_n_flags, info->band);
}

#ifdef CONFIG_IWLWIFI_DEBUG
const char *iwl_get_tx_fail_reason(u32 status)
{
#define TX_STATUS_FAIL(x) case TX_STATUS_FAIL_ ## x: return #x
#define TX_STATUS_POSTPONE(x) case TX_STATUS_POSTPONE_ ## x: return #x

    switch (status & TX_STATUS_MSK) {
    case TX_STATUS_SUCCESS:
        return "SUCCESS";
    TX_STATUS_POSTPONE(DELAY);
    TX_STATUS_POSTPONE(FEW_BYTES);
    TX_STATUS_POSTPONE(BT_PRIO);
    TX_STATUS_POSTPONE(QUIET_PERIOD);
    TX_STATUS_POSTPONE(CALC_TTAK);
    TX_STATUS_FAIL(INTERNAL_CROSSED_RETRY);
    TX_STATUS_FAIL(SHORT_LIMIT);
    TX_STATUS_FAIL(LONG_LIMIT);
    TX_STATUS_FAIL(FIFO_UNDERRUN);
    TX_STATUS_FAIL(DRAIN_FLOW);
    TX_STATUS_FAIL(RFKILL_FLUSH);
    TX_STATUS_FAIL(LIFE_EXPIRE);
    TX_STATUS_FAIL(DEST_PS);
    TX_STATUS_FAIL(HOST_ABORTED);
    TX_STATUS_FAIL(BT_RETRY);
    TX_STATUS_FAIL(STA_INVALID);
    TX_STATUS_FAIL(FRAG_DROPPED);
    TX_STATUS_FAIL(TID_DISABLE);
    TX_STATUS_FAIL(FIFO_FLUSHED);
    TX_STATUS_FAIL(INSUFFICIENT_CF_POLL);
    TX_STATUS_FAIL(PASSIVE_NO_RX);
    TX_STATUS_FAIL(NO_BEACON_ON_RADAR);
    }

    return "UNKNOWN";

#undef TX_STATUS_FAIL
#undef TX_STATUS_POSTPONE
}
#endif /* CONFIG_IWLWIFI_DEBUG */

static void iwlagn_count_agg_tx_err_status(struct iwl_priv *priv, u16 status)
{
    status &= AGG_TX_STATUS_MSK;

    switch (status) {
    case AGG_TX_STATE_UNDERRUN_MSK:
        priv->reply_agg_tx_stats.underrun++;
        break;
    case AGG_TX_STATE_BT_PRIO_MSK:
        priv->reply_agg_tx_stats.bt_prio++;
        break;
    case AGG_TX_STATE_FEW_BYTES_MSK:
        priv->reply_agg_tx_stats.few_bytes++;
        break;
    case AGG_TX_STATE_ABORT_MSK:
        priv->reply_agg_tx_stats.abort++;
        break;
    case AGG_TX_STATE_LAST_SENT_TTL_MSK:
        priv->reply_agg_tx_stats.last_sent_ttl++;
        break;
    case AGG_TX_STATE_LAST_SENT_TRY_CNT_MSK:
        priv->reply_agg_tx_stats.last_sent_try++;
        break;
    case AGG_TX_STATE_LAST_SENT_BT_KILL_MSK:
        priv->reply_agg_tx_stats.last_sent_bt_kill++;
        break;
    case AGG_TX_STATE_SCD_QUERY_MSK:
        priv->reply_agg_tx_stats.scd_query++;
        break;
    case AGG_TX_STATE_TEST_BAD_CRC32_MSK:
        priv->reply_agg_tx_stats.bad_crc32++;
        break;
    case AGG_TX_STATE_RESPONSE_MSK:
        priv->reply_agg_tx_stats.response++;
        break;
    case AGG_TX_STATE_DUMP_TX_MSK:
        priv->reply_agg_tx_stats.dump_tx++;
        break;
    case AGG_TX_STATE_DELAY_TX_MSK:
        priv->reply_agg_tx_stats.delay_tx++;
        break;
    default:
        priv->reply_agg_tx_stats.unknown++;
        break;
    }
}

static void iwl_rx_reply_tx_agg(struct iwl_priv *priv,
                struct iwlagn_tx_resp *tx_resp)
{
    struct agg_tx_status *frame_status = &tx_resp->status;
    int tid = (tx_resp->ra_tid & IWLAGN_TX_RES_TID_MSK) >>
        IWLAGN_TX_RES_TID_POS;
    int sta_id = (tx_resp->ra_tid & IWLAGN_TX_RES_RA_MSK) >>
        IWLAGN_TX_RES_RA_POS;
    struct iwl_ht_agg *agg = &priv->tid_data[sta_id][tid].agg;
    u32 status = le16_to_cpu(tx_resp->status.status);
    int i;

    WARN_ON(tid == IWL_TID_NON_QOS);

    if (agg->wait_for_ba)
        IWL_DEBUG_TX_REPLY(priv,
            "got tx response w/o block-ack\n");

    agg->rate_n_flags = le32_to_cpu(tx_resp->rate_n_flags);
    agg->wait_for_ba = (tx_resp->frame_count > 1);

    /*
     * If the BT kill count is non-zero, we'll get this
     * notification again.
     */
    if (tx_resp->bt_kill_count && tx_resp->frame_count == 1 &&
        priv->cfg->bt_params &&
        priv->cfg->bt_params->advanced_bt_coexist) {
        IWL_DEBUG_COEX(priv, "receive reply tx w/ bt_kill\n");
    }

    if (tx_resp->frame_count == 1)
        return;

    /* Construct bit-map of pending frames within Tx window */
    for (i = 0; i < tx_resp->frame_count; i++) {
        u16 fstatus = le16_to_cpu(frame_status[i].status);

        if (status & AGG_TX_STATUS_MSK)
            iwlagn_count_agg_tx_err_status(priv, fstatus);

        if (status & (AGG_TX_STATE_FEW_BYTES_MSK |
                  AGG_TX_STATE_ABORT_MSK))
            continue;

        IWL_DEBUG_TX_REPLY(priv, "status %s (0x%08x), "
                   "try-count (0x%08x)\n",
                   iwl_get_agg_tx_fail_reason(fstatus),
                   fstatus & AGG_TX_STATUS_MSK,
                   fstatus & AGG_TX_TRY_MSK);
    }
}

#ifdef CONFIG_IWLWIFI_DEBUG
#define AGG_TX_STATE_FAIL(x) case AGG_TX_STATE_ ## x: return #x

const char *iwl_get_agg_tx_fail_reason(u16 status)
{
    status &= AGG_TX_STATUS_MSK;
    switch (status) {
    case AGG_TX_STATE_TRANSMITTED:
        return "SUCCESS";
        AGG_TX_STATE_FAIL(UNDERRUN_MSK);
        AGG_TX_STATE_FAIL(BT_PRIO_MSK);
        AGG_TX_STATE_FAIL(FEW_BYTES_MSK);
        AGG_TX_STATE_FAIL(ABORT_MSK);
        AGG_TX_STATE_FAIL(LAST_SENT_TTL_MSK);
        AGG_TX_STATE_FAIL(LAST_SENT_TRY_CNT_MSK);
        AGG_TX_STATE_FAIL(LAST_SENT_BT_KILL_MSK);
        AGG_TX_STATE_FAIL(SCD_QUERY_MSK);
        AGG_TX_STATE_FAIL(TEST_BAD_CRC32_MSK);
        AGG_TX_STATE_FAIL(RESPONSE_MSK);
        AGG_TX_STATE_FAIL(DUMP_TX_MSK);
        AGG_TX_STATE_FAIL(DELAY_TX_MSK);
    }

    return "UNKNOWN";
}
#endif /* CONFIG_IWLWIFI_DEBUG */

static inline u32 iwlagn_get_scd_ssn(struct iwlagn_tx_resp *tx_resp)
{
    return le32_to_cpup((__le32 *)&tx_resp->status +
                tx_resp->frame_count) & MAX_SN;
}

static void iwlagn_count_tx_err_status(struct iwl_priv *priv, u16 status)
{
    status &= TX_STATUS_MSK;

    switch (status) {
    case TX_STATUS_POSTPONE_DELAY:
        priv->reply_tx_stats.pp_delay++;
        break;
    case TX_STATUS_POSTPONE_FEW_BYTES:
        priv->reply_tx_stats.pp_few_bytes++;
        break;
    case TX_STATUS_POSTPONE_BT_PRIO:
        priv->reply_tx_stats.pp_bt_prio++;
        break;
    case TX_STATUS_POSTPONE_QUIET_PERIOD:
        priv->reply_tx_stats.pp_quiet_period++;
        break;
    case TX_STATUS_POSTPONE_CALC_TTAK:
        priv->reply_tx_stats.pp_calc_ttak++;
        break;
    case TX_STATUS_FAIL_INTERNAL_CROSSED_RETRY:
        priv->reply_tx_stats.int_crossed_retry++;
        break;
    case TX_STATUS_FAIL_SHORT_LIMIT:
        priv->reply_tx_stats.short_limit++;
        break;
    case TX_STATUS_FAIL_LONG_LIMIT:
        priv->reply_tx_stats.long_limit++;
        break;
    case TX_STATUS_FAIL_FIFO_UNDERRUN:
        priv->reply_tx_stats.fifo_underrun++;
        break;
    case TX_STATUS_FAIL_DRAIN_FLOW:
        priv->reply_tx_stats.drain_flow++;
        break;
    case TX_STATUS_FAIL_RFKILL_FLUSH:
        priv->reply_tx_stats.rfkill_flush++;
        break;
    case TX_STATUS_FAIL_LIFE_EXPIRE:
        priv->reply_tx_stats.life_expire++;
        break;
    case TX_STATUS_FAIL_DEST_PS:
        priv->reply_tx_stats.dest_ps++;
        break;
    case TX_STATUS_FAIL_HOST_ABORTED:
        priv->reply_tx_stats.host_abort++;
        break;
    case TX_STATUS_FAIL_BT_RETRY:
        priv->reply_tx_stats.bt_retry++;
        break;
    case TX_STATUS_FAIL_STA_INVALID:
        priv->reply_tx_stats.sta_invalid++;
        break;
    case TX_STATUS_FAIL_FRAG_DROPPED:
        priv->reply_tx_stats.frag_drop++;
        break;
    case TX_STATUS_FAIL_TID_DISABLE:
        priv->reply_tx_stats.tid_disable++;
        break;
    case TX_STATUS_FAIL_FIFO_FLUSHED:
        priv->reply_tx_stats.fifo_flush++;
        break;
    case TX_STATUS_FAIL_INSUFFICIENT_CF_POLL:
        priv->reply_tx_stats.insuff_cf_poll++;
        break;
    case TX_STATUS_FAIL_PASSIVE_NO_RX:
        priv->reply_tx_stats.fail_hw_drop++;
        break;
    case TX_STATUS_FAIL_NO_BEACON_ON_RADAR:
        priv->reply_tx_stats.sta_color_mismatch++;
        break;
    default:
        priv->reply_tx_stats.unknown++;
        break;
    }
}

static void iwlagn_set_tx_status(struct iwl_priv *priv,
                 struct ieee80211_tx_info *info,
                 struct iwlagn_tx_resp *tx_resp,
                 bool is_agg)
{
    u16  status = le16_to_cpu(tx_resp->status.status);

    info->status.rates[0].count = tx_resp->failure_frame + 1;
    if (is_agg)
        info->flags &= ~IEEE80211_TX_CTL_AMPDU;
    info->flags |= iwl_tx_status_to_mac80211(status);
    iwlagn_hwrate_to_tx_control(priv, le32_to_cpu(tx_resp->rate_n_flags),
                    info);
    if (!iwl_is_tx_success(status))
        iwlagn_count_tx_err_status(priv, status);
}

static void iwl_check_abort_status(struct iwl_priv *priv,
                u8 frame_count, u32 status)
{
    if (frame_count == 1 && status == TX_STATUS_FAIL_RFKILL_FLUSH) {
        IWL_ERR(priv, "Tx flush command to flush out all frames\n");
        if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
            queue_work(priv->workqueue, &priv->tx_flush);
    }
}

static int iwl_reclaim(struct iwl_priv *priv, int sta_id, int tid,
               int txq_id, int ssn, struct sk_buff_head *skbs)
{
    if (unlikely(txq_id >= IWLAGN_FIRST_AMPDU_QUEUE &&
             tid != IWL_TID_NON_QOS &&
             txq_id != priv->tid_data[sta_id][tid].agg.txq_id)) {
        /*
         * FIXME: this is a uCode bug which need to be addressed,
         * log the information and return for now.
         * Since it is can possibly happen very often and in order
         * not to fill the syslog, don't use IWL_ERR or IWL_WARN
         */
        IWL_DEBUG_TX_QUEUES(priv,
            "Bad queue mapping txq_id=%d, agg_txq[sta:%d,tid:%d]=%d\n",
            txq_id, sta_id, tid,
            priv->tid_data[sta_id][tid].agg.txq_id);
        return 1;
    }

    iwl_trans_reclaim(priv->trans, txq_id, ssn, skbs);
    return 0;
}

int iwlagn_rx_reply_tx(struct iwl_priv *priv, struct iwl_rx_cmd_buffer *rxb,
                   struct iwl_device_cmd *cmd)
{
    struct iwl_rx_packet *pkt = rxb_addr(rxb);
    u16 sequence = le16_to_cpu(pkt->hdr.sequence);
    int txq_id = SEQ_TO_QUEUE(sequence);
    int cmd_index __maybe_unused = SEQ_TO_INDEX(sequence);
    struct iwlagn_tx_resp *tx_resp = (void *)pkt->data;
    struct ieee80211_hdr *hdr;
    u32 status = le16_to_cpu(tx_resp->status.status);
    u16 ssn = iwlagn_get_scd_ssn(tx_resp);
    int tid;
    int sta_id;
    int freed;
    struct ieee80211_tx_info *info;
    struct sk_buff_head skbs;
    struct sk_buff *skb;
    struct iwl_rxon_context *ctx;
    bool is_agg = (txq_id >= IWLAGN_FIRST_AMPDU_QUEUE);
    bool is_offchannel_skb;

    tid = (tx_resp->ra_tid & IWLAGN_TX_RES_TID_MSK) >>
        IWLAGN_TX_RES_TID_POS;
    sta_id = (tx_resp->ra_tid & IWLAGN_TX_RES_RA_MSK) >>
        IWLAGN_TX_RES_RA_POS;

    spin_lock(&priv->sta_lock);

    if (is_agg)
        iwl_rx_reply_tx_agg(priv, tx_resp);

    __skb_queue_head_init(&skbs);

    is_offchannel_skb = false;

    if (tx_resp->frame_count == 1) {
        u16 next_reclaimed = le16_to_cpu(tx_resp->seq_ctl);
        next_reclaimed = SEQ_TO_SN(next_reclaimed + 0x10);

        if (is_agg) {
            /* If this is an aggregation queue, we can rely on the
             * ssn since the wifi sequence number corresponds to
             * the index in the TFD ring (%256).
             * The seq_ctl is the sequence control of the packet
             * to which this Tx response relates. But if there is a
             * hole in the bitmap of the BA we received, this Tx
             * response may allow to reclaim the hole and all the
             * subsequent packets that were already acked.
             * In that case, seq_ctl != ssn, and the next packet
             * to be reclaimed will be ssn and not seq_ctl.
             */
            next_reclaimed = ssn;
        }

        if (tid != IWL_TID_NON_QOS) {
            priv->tid_data[sta_id][tid].next_reclaimed =
                next_reclaimed;
            IWL_DEBUG_TX_REPLY(priv, "Next reclaimed packet:%d\n",
                          next_reclaimed);
        }

        /*we can free until ssn % q.n_bd not inclusive */
        WARN_ON_ONCE(iwl_reclaim(priv, sta_id, tid,
                     txq_id, ssn, &skbs));
        iwlagn_check_ratid_empty(priv, sta_id, tid);
        freed = 0;

        /* process frames */
        skb_queue_walk(&skbs, skb) {
            hdr = (struct ieee80211_hdr *)skb->data;

            if (!ieee80211_is_data_qos(hdr->frame_control))
                priv->last_seq_ctl = tx_resp->seq_ctl;

            info = IEEE80211_SKB_CB(skb);
            ctx = info->driver_data[0];
            iwl_trans_free_tx_cmd(priv->trans,
                          info->driver_data[1]);

            memset(&info->status, 0, sizeof(info->status));

            if (status == TX_STATUS_FAIL_PASSIVE_NO_RX &&
                iwl_is_associated_ctx(ctx) && ctx->vif &&
                ctx->vif->type == NL80211_IFTYPE_STATION) {
                /* block and stop all queues */
                priv->passive_no_rx = true;
                IWL_DEBUG_TX_QUEUES(priv, "stop all queues: "
                            "passive channel");
                ieee80211_stop_queues(priv->hw);

                IWL_DEBUG_TX_REPLY(priv,
                       "TXQ %d status %s (0x%08x) "
                       "rate_n_flags 0x%x retries %d\n",
                       txq_id,
                       iwl_get_tx_fail_reason(status),
                       status,
                       le32_to_cpu(tx_resp->rate_n_flags),
                       tx_resp->failure_frame);

                IWL_DEBUG_TX_REPLY(priv,
                       "FrameCnt = %d, idx=%d\n",
                       tx_resp->frame_count, cmd_index);
            }

            /* check if BAR is needed */
            if (is_agg && !iwl_is_tx_success(status))
                info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
            iwlagn_set_tx_status(priv, IEEE80211_SKB_CB(skb),
                     tx_resp, is_agg);
            if (!is_agg)
                iwlagn_non_agg_tx_status(priv, ctx, hdr->addr1);

            is_offchannel_skb =
                (info->flags & IEEE80211_TX_CTL_TX_OFFCHAN);
            freed++;
        }

        WARN_ON(!is_agg && freed != 1);

        /*
         * An offchannel frame can be send only on the AUX queue, where
         * there is no aggregation (and reordering) so it only is single
         * skb is expected to be processed.
         */
        WARN_ON(is_offchannel_skb && freed != 1);
    }

    iwl_check_abort_status(priv, tx_resp->frame_count, status);
    spin_unlock(&priv->sta_lock);

    while (!skb_queue_empty(&skbs)) {
        skb = __skb_dequeue(&skbs);
        ieee80211_tx_status(priv->hw, skb);
    }

    if (is_offchannel_skb)
        iwl_scan_offchannel_skb_status(priv);

    return 0;
}

int iwlagn_rx_reply_compressed_ba(struct iwl_priv *priv,
                   struct iwl_rx_cmd_buffer *rxb,
                   struct iwl_device_cmd *cmd)
{
    struct iwl_rx_packet *pkt = rxb_addr(rxb);
    struct iwl_compressed_ba_resp *ba_resp = (void *)pkt->data;
    struct iwl_ht_agg *agg;
    struct sk_buff_head reclaimed_skbs;
    struct ieee80211_tx_info *info;
    struct ieee80211_hdr *hdr;
    struct sk_buff *skb;
    int sta_id;
    int tid;
    int freed;

    /* "flow" corresponds to Tx queue */
    u16 scd_flow = le16_to_cpu(ba_resp->scd_flow);

    /* "ssn" is start of block-ack Tx window, corresponds to index
     * (in Tx queue's circular buffer) of first TFD/frame in window */
    u16 ba_resp_scd_ssn = le16_to_cpu(ba_resp->scd_ssn);

    if (scd_flow >= priv->cfg->base_params->num_of_queues) {
        IWL_ERR(priv,
            "BUG_ON scd_flow is bigger than number of queues\n");
        return 0;
    }

    sta_id = ba_resp->sta_id;
    tid = ba_resp->tid;
    agg = &priv->tid_data[sta_id][tid].agg;

    spin_lock(&priv->sta_lock);

    if (unlikely(!agg->wait_for_ba)) {
        if (unlikely(ba_resp->bitmap))
            IWL_ERR(priv, "Received BA when not expected\n");
        spin_unlock(&priv->sta_lock);
        return 0;
    }

    __skb_queue_head_init(&reclaimed_skbs);

    /* Release all TFDs before the SSN, i.e. all TFDs in front of
     * block-ack window (we assume that they've been successfully
     * transmitted ... if not, it's too late anyway). */
    if (iwl_reclaim(priv, sta_id, tid, scd_flow,
            ba_resp_scd_ssn, &reclaimed_skbs)) {
        spin_unlock(&priv->sta_lock);
        return 0;
    }

    IWL_DEBUG_TX_REPLY(priv, "REPLY_COMPRESSED_BA [%d] Received from %pM, "
               "sta_id = %d\n",
               agg->wait_for_ba,
               (u8 *) &ba_resp->sta_addr_lo32,
               ba_resp->sta_id);
    IWL_DEBUG_TX_REPLY(priv, "TID = %d, SeqCtl = %d, bitmap = 0x%llx, "
               "scd_flow = %d, scd_ssn = %d sent:%d, acked:%d\n",
               ba_resp->tid, le16_to_cpu(ba_resp->seq_ctl),
               (unsigned long long)le64_to_cpu(ba_resp->bitmap),
               scd_flow, ba_resp_scd_ssn, ba_resp->txed,
               ba_resp->txed_2_done);

    /* Mark that the expected block-ack response arrived */
    agg->wait_for_ba = false;

    /* Sanity check values reported by uCode */
    if (ba_resp->txed_2_done > ba_resp->txed) {
        IWL_DEBUG_TX_REPLY(priv,
            "bogus sent(%d) and ack(%d) count\n",
            ba_resp->txed, ba_resp->txed_2_done);
        /*
         * set txed_2_done = txed,
         * so it won't impact rate scale
         */
        ba_resp->txed = ba_resp->txed_2_done;
    }

    priv->tid_data[sta_id][tid].next_reclaimed = ba_resp_scd_ssn;

    iwlagn_check_ratid_empty(priv, sta_id, tid);
    freed = 0;

    skb_queue_walk(&reclaimed_skbs, skb) {
        hdr = (struct ieee80211_hdr *)skb->data;

        if (ieee80211_is_data_qos(hdr->frame_control))
            freed++;
        else
            WARN_ON_ONCE(1);

        info = IEEE80211_SKB_CB(skb);
        iwl_trans_free_tx_cmd(priv->trans, info->driver_data[1]);

        if (freed == 1) {
            /* this is the first skb we deliver in this batch */
            /* put the rate scaling data there */
            info = IEEE80211_SKB_CB(skb);
            memset(&info->status, 0, sizeof(info->status));
            info->flags |= IEEE80211_TX_STAT_ACK;
            info->flags |= IEEE80211_TX_STAT_AMPDU;
            info->status.ampdu_ack_len = ba_resp->txed_2_done;
            info->status.ampdu_len = ba_resp->txed;
            iwlagn_hwrate_to_tx_control(priv, agg->rate_n_flags,
                            info);
        }
    }

    spin_unlock(&priv->sta_lock);

    while (!skb_queue_empty(&reclaimed_skbs)) {
        skb = __skb_dequeue(&reclaimed_skbs);
        ieee80211_tx_status(priv->hw, skb);
    }

    return 0;
}