/*
 * Atheros AR9170 driver
 *
 * mac80211 interaction code
 *
 * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
 * Copyright 2009, Christian Lamparter <chunkeey@web.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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; see the file COPYING.  If not, see
 * http://www.gnu.org/licenses/.
 *
 * This file incorporates work covered by the following copyright and
 * permission notice:
 *    Copyright (c) 2007-2008 Atheros Communications, Inc.
 *
 *    Permission to use, copy, modify, and/or distribute this software for any
 *    purpose with or without fee is hereby granted, provided that the above
 *    copyright notice and this permission notice appear in all copies.
 *
 *    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/etherdevice.h>
#include <net/mac80211.h>
#include "ar9170.h"
#include "hw.h"
#include "cmd.h"

static int modparam_nohwcrypt;
module_param_named(nohwcrypt, modparam_nohwcrypt, bool, S_IRUGO);
MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");

#define RATE(_bitrate, _hw_rate, _txpidx, _flags) {     \
        .bitrate        = (_bitrate),                   \
        .flags          = (_flags),                     \
        .hw_value       = (_hw_rate) | (_txpidx) << 4,  \
}

static struct ieee80211_rate __ar9170_ratetable[] = {
        RATE(10, 0, 0, 0),
        RATE(20, 1, 1, IEEE80211_RATE_SHORT_PREAMBLE),
        RATE(55, 2, 2, IEEE80211_RATE_SHORT_PREAMBLE),
        RATE(110, 3, 3, IEEE80211_RATE_SHORT_PREAMBLE),
        RATE(60, 0xb, 0, 0),
        RATE(90, 0xf, 0, 0),
        RATE(120, 0xa, 0, 0),
        RATE(180, 0xe, 0, 0),
        RATE(240, 0x9, 0, 0),
        RATE(360, 0xd, 1, 0),
        RATE(480, 0x8, 2, 0),
        RATE(540, 0xc, 3, 0),
};
#undef RATE

#define ar9170_g_ratetable      (__ar9170_ratetable + 0)
#define ar9170_g_ratetable_size 12
#define ar9170_a_ratetable      (__ar9170_ratetable + 4)
#define ar9170_a_ratetable_size 8

/*
 * NB: The hw_value is used as an index into the ar9170_phy_freq_params
 *     array in phy.c so that we don't have to do frequency lookups!
 */
#define CHAN(_freq, _idx) {             \
        .center_freq    = (_freq),      \
        .hw_value       = (_idx),       \
        .max_power      = 18, /* XXX */ \
}

static struct ieee80211_channel ar9170_2ghz_chantable[] = {
        CHAN(2412,  0),
        CHAN(2417,  1),
        CHAN(2422,  2),
        CHAN(2427,  3),
        CHAN(2432,  4),
        CHAN(2437,  5),
        CHAN(2442,  6),
        CHAN(2447,  7),
        CHAN(2452,  8),
        CHAN(2457,  9),
        CHAN(2462, 10),
        CHAN(2467, 11),
        CHAN(2472, 12),
        CHAN(2484, 13),
};

static struct ieee80211_channel ar9170_5ghz_chantable[] = {
        CHAN(4920, 14),
        CHAN(4940, 15),
        CHAN(4960, 16),
        CHAN(4980, 17),
        CHAN(5040, 18),
        CHAN(5060, 19),
        CHAN(5080, 20),
        CHAN(5180, 21),
        CHAN(5200, 22),
        CHAN(5220, 23),
        CHAN(5240, 24),
        CHAN(5260, 25),
        CHAN(5280, 26),
        CHAN(5300, 27),
        CHAN(5320, 28),
        CHAN(5500, 29),
        CHAN(5520, 30),
        CHAN(5540, 31),
        CHAN(5560, 32),
        CHAN(5580, 33),
        CHAN(5600, 34),
        CHAN(5620, 35),
        CHAN(5640, 36),
        CHAN(5660, 37),
        CHAN(5680, 38),
        CHAN(5700, 39),
        CHAN(5745, 40),
        CHAN(5765, 41),
        CHAN(5785, 42),
        CHAN(5805, 43),
        CHAN(5825, 44),
        CHAN(5170, 45),
        CHAN(5190, 46),
        CHAN(5210, 47),
        CHAN(5230, 48),
};
#undef CHAN

#define AR9170_HT_CAP                                                   \
{                                                                       \
        .ht_supported   = true,                                         \
        .cap            = IEEE80211_HT_CAP_MAX_AMSDU |                  \
                          IEEE80211_HT_CAP_SUP_WIDTH_20_40 |            \
                          IEEE80211_HT_CAP_SGI_40 |                     \
                          IEEE80211_HT_CAP_GRN_FLD |                    \
                          IEEE80211_HT_CAP_DSSSCCK40 |                  \
                          IEEE80211_HT_CAP_SM_PS,                       \
        .ampdu_factor   = 3,                                            \
        .ampdu_density  = 6,                                            \
        .mcs            = {                                             \
                .rx_mask = { 0xff, 0xff, 0, 0, 0x1, 0, 0, 0, 0, 0, },   \
                .rx_highest = cpu_to_le16(300),                         \
                .tx_params = IEEE80211_HT_MCS_TX_DEFINED,               \
        },                                                              \
}

static struct ieee80211_supported_band ar9170_band_2GHz = {
        .channels       = ar9170_2ghz_chantable,
        .n_channels     = ARRAY_SIZE(ar9170_2ghz_chantable),
        .bitrates       = ar9170_g_ratetable,
        .n_bitrates     = ar9170_g_ratetable_size,
        .ht_cap         = AR9170_HT_CAP,
};

static struct ieee80211_supported_band ar9170_band_5GHz = {
        .channels       = ar9170_5ghz_chantable,
        .n_channels     = ARRAY_SIZE(ar9170_5ghz_chantable),
        .bitrates       = ar9170_a_ratetable,
        .n_bitrates     = ar9170_a_ratetable_size,
        .ht_cap         = AR9170_HT_CAP,
};

static void ar9170_tx(struct ar9170 *ar);

static inline u16 ar9170_get_seq_h(struct ieee80211_hdr *hdr)
{
        return le16_to_cpu(hdr->seq_ctrl) >> 4;
}

static inline u16 ar9170_get_seq(struct sk_buff *skb)
{
        struct ar9170_tx_control *txc = (void *) skb->data;
        return ar9170_get_seq_h((void *) txc->frame_data);
}

#ifdef AR9170_QUEUE_DEBUG
static void ar9170_print_txheader(struct ar9170 *ar, struct sk_buff *skb)
{
        struct ar9170_tx_control *txc = (void *) skb->data;
        struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
        struct ar9170_tx_info *arinfo = (void *) txinfo->rate_driver_data;
        struct ieee80211_hdr *hdr = (void *) txc->frame_data;

        wiphy_debug(ar->hw->wiphy,
                    "=> FRAME [skb:%p, q:%d, DA:[%pM] s:%d "
                    "mac_ctrl:%04x, phy_ctrl:%08x, timeout:[%d ms]]\n",
                    skb, skb_get_queue_mapping(skb),
                    ieee80211_get_DA(hdr), ar9170_get_seq_h(hdr),
                    le16_to_cpu(txc->mac_control), le32_to_cpu(txc->phy_control),
                    jiffies_to_msecs(arinfo->timeout - jiffies));
}

static void __ar9170_dump_txqueue(struct ar9170 *ar,
                                struct sk_buff_head *queue)
{
        struct sk_buff *skb;
        int i = 0;

        printk(KERN_DEBUG "---[ cut here ]---\n");
        wiphy_debug(ar->hw->wiphy, "%d entries in queue.\n",
                    skb_queue_len(queue));

        skb_queue_walk(queue, skb) {
                printk(KERN_DEBUG "index:%d =>\n", i++);
                ar9170_print_txheader(ar, skb);
        }
        if (i != skb_queue_len(queue))
                printk(KERN_DEBUG "WARNING: queue frame counter "
                       "mismatch %d != %d\n", skb_queue_len(queue), i);
        printk(KERN_DEBUG "---[ end ]---\n");
}
#endif /* AR9170_QUEUE_DEBUG */

#ifdef AR9170_QUEUE_DEBUG
static void ar9170_dump_txqueue(struct ar9170 *ar,
                                struct sk_buff_head *queue)
{
        unsigned long flags;

        spin_lock_irqsave(&queue->lock, flags);
        __ar9170_dump_txqueue(ar, queue);
        spin_unlock_irqrestore(&queue->lock, flags);
}
#endif /* AR9170_QUEUE_DEBUG */

#ifdef AR9170_QUEUE_STOP_DEBUG
static void __ar9170_dump_txstats(struct ar9170 *ar)
{
        int i;

        wiphy_debug(ar->hw->wiphy, "QoS queue stats\n");

        for (i = 0; i < __AR9170_NUM_TXQ; i++)
                wiphy_debug(ar->hw->wiphy,
                            "queue:%d limit:%d len:%d waitack:%d stopped:%d\n",
                            i, ar->tx_stats[i].limit, ar->tx_stats[i].len,
                            skb_queue_len(&ar->tx_status[i]),
                            ieee80211_queue_stopped(ar->hw, i));
}
#endif /* AR9170_QUEUE_STOP_DEBUG */

/* caller must guarantee exclusive access for _bin_ queue. */
static void ar9170_recycle_expired(struct ar9170 *ar,
                                   struct sk_buff_head *queue,
                                   struct sk_buff_head *bin)
{
        struct sk_buff *skb, *old = NULL;
        unsigned long flags;

        spin_lock_irqsave(&queue->lock, flags);
        while ((skb = skb_peek(queue))) {
                struct ieee80211_tx_info *txinfo;
                struct ar9170_tx_info *arinfo;

                txinfo = IEEE80211_SKB_CB(skb);
                arinfo = (void *) txinfo->rate_driver_data;

                if (time_is_before_jiffies(arinfo->timeout)) {
#ifdef AR9170_QUEUE_DEBUG
                        wiphy_debug(ar->hw->wiphy,
                                    "[%ld > %ld] frame expired => recycle\n",
                                    jiffies, arinfo->timeout);
                        ar9170_print_txheader(ar, skb);
#endif /* AR9170_QUEUE_DEBUG */
                        __skb_unlink(skb, queue);
                        __skb_queue_tail(bin, skb);
                } else {
                        break;
                }

                if (unlikely(old == skb)) {
                        /* bail out - queue is shot. */

                        WARN_ON(1);
                        break;
                }
                old = skb;
        }
        spin_unlock_irqrestore(&queue->lock, flags);
}

static void ar9170_tx_status(struct ar9170 *ar, struct sk_buff *skb,
                                    u16 tx_status)
{
        struct ieee80211_tx_info *txinfo;
        unsigned int retries = 0;

        txinfo = IEEE80211_SKB_CB(skb);
        ieee80211_tx_info_clear_status(txinfo);

        switch (tx_status) {
        case AR9170_TX_STATUS_RETRY:
                retries = 2;
        case AR9170_TX_STATUS_COMPLETE:
                txinfo->flags |= IEEE80211_TX_STAT_ACK;
                break;

        case AR9170_TX_STATUS_FAILED:
                retries = ar->hw->conf.long_frame_max_tx_count;
                break;

        default:
                wiphy_err(ar->hw->wiphy,
                          "invalid tx_status response (%x)\n", tx_status);
                break;
        }

        txinfo->status.rates[0].count = retries + 1;
        skb_pull(skb, sizeof(struct ar9170_tx_control));
        ieee80211_tx_status_irqsafe(ar->hw, skb);
}

void ar9170_tx_callback(struct ar9170 *ar, struct sk_buff *skb)
{
        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
        struct ar9170_tx_info *arinfo = (void *) info->rate_driver_data;
        unsigned int queue = skb_get_queue_mapping(skb);
        unsigned long flags;

        spin_lock_irqsave(&ar->tx_stats_lock, flags);
        ar->tx_stats[queue].len--;

        if (ar->tx_stats[queue].len < AR9170_NUM_TX_LIMIT_SOFT) {
#ifdef AR9170_QUEUE_STOP_DEBUG
                wiphy_debug(ar->hw->wiphy, "wake queue %d\n", queue);
                __ar9170_dump_txstats(ar);
#endif /* AR9170_QUEUE_STOP_DEBUG */
                ieee80211_wake_queue(ar->hw, queue);
        }
        spin_unlock_irqrestore(&ar->tx_stats_lock, flags);

        if (info->flags & IEEE80211_TX_CTL_NO_ACK) {
                ar9170_tx_status(ar, skb, AR9170_TX_STATUS_FAILED);
        } else {
                arinfo->timeout = jiffies +
                          msecs_to_jiffies(AR9170_TX_TIMEOUT);

                skb_queue_tail(&ar->tx_status[queue], skb);
        }

        if (!ar->tx_stats[queue].len &&
            !skb_queue_empty(&ar->tx_pending[queue])) {
                ar9170_tx(ar);
        }
}

static struct sk_buff *ar9170_get_queued_skb(struct ar9170 *ar,
                                             const u8 *mac,
                                             struct sk_buff_head *queue,
                                             const u32 rate)
{
        unsigned long flags;
        struct sk_buff *skb;

        /*
         * Unfortunately, the firmware does not tell to which (queued) frame
         * this transmission status report belongs to.
         *
         * So we have to make risky guesses - with the scarce information
         * the firmware provided (-> destination MAC, and phy_control) -
         * and hope that we picked the right one...
         */

        spin_lock_irqsave(&queue->lock, flags);
        skb_queue_walk(queue, skb) {
                struct ar9170_tx_control *txc = (void *) skb->data;
                struct ieee80211_hdr *hdr = (void *) txc->frame_data;
                u32 r;

                if (mac && compare_ether_addr(ieee80211_get_DA(hdr), mac)) {
#ifdef AR9170_QUEUE_DEBUG
                        wiphy_debug(ar->hw->wiphy,
                                    "skip frame => DA %pM != %pM\n",
                                    mac, ieee80211_get_DA(hdr));
                        ar9170_print_txheader(ar, skb);
#endif /* AR9170_QUEUE_DEBUG */
                        continue;
                }

                r = (le32_to_cpu(txc->phy_control) & AR9170_TX_PHY_MCS_MASK) >>
                    AR9170_TX_PHY_MCS_SHIFT;

                if ((rate != AR9170_TX_INVALID_RATE) && (r != rate)) {
#ifdef AR9170_QUEUE_DEBUG
                        wiphy_debug(ar->hw->wiphy,
                                    "skip frame => rate %d != %d\n", rate, r);
                        ar9170_print_txheader(ar, skb);
#endif /* AR9170_QUEUE_DEBUG */
                        continue;
                }

                __skb_unlink(skb, queue);
                spin_unlock_irqrestore(&queue->lock, flags);
                return skb;
        }

#ifdef AR9170_QUEUE_DEBUG
        wiphy_err(ar->hw->wiphy,
                  "ESS:[%pM] does not have any outstanding frames in queue.\n",
                  mac);
        __ar9170_dump_txqueue(ar, queue);
#endif /* AR9170_QUEUE_DEBUG */
        spin_unlock_irqrestore(&queue->lock, flags);

        return NULL;
}

/*
 * This worker tries to keeps an maintain tx_status queues.
 * So we can guarantee that incoming tx_status reports are
 * actually for a pending frame.
 */

static void ar9170_tx_janitor(struct work_struct *work)
{
        struct ar9170 *ar = container_of(work, struct ar9170,
                                         tx_janitor.work);
        struct sk_buff_head waste;
        unsigned int i;
        bool resched = false;

        if (unlikely(!IS_STARTED(ar)))
                return ;

        skb_queue_head_init(&waste);

        for (i = 0; i < __AR9170_NUM_TXQ; i++) {
#ifdef AR9170_QUEUE_DEBUG
                wiphy_debug(ar->hw->wiphy, "garbage collector scans queue:%d\n",
                            i);
                ar9170_dump_txqueue(ar, &ar->tx_pending[i]);
                ar9170_dump_txqueue(ar, &ar->tx_status[i]);
#endif /* AR9170_QUEUE_DEBUG */

                ar9170_recycle_expired(ar, &ar->tx_status[i], &waste);
                ar9170_recycle_expired(ar, &ar->tx_pending[i], &waste);
                skb_queue_purge(&waste);

                if (!skb_queue_empty(&ar->tx_status[i]) ||
                    !skb_queue_empty(&ar->tx_pending[i]))
                        resched = true;
        }

        if (!resched)
                return;

        ieee80211_queue_delayed_work(ar->hw,
                                     &ar->tx_janitor,
                                     msecs_to_jiffies(AR9170_JANITOR_DELAY));
}

void ar9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len)
{
        struct ar9170_cmd_response *cmd = (void *) buf;

        if ((cmd->type & 0xc0) != 0xc0) {
                ar->callback_cmd(ar, len, buf);
                return;
        }

        /* hardware event handlers */
        switch (cmd->type) {
        case 0xc1: {
                /*
                 * TX status notification:
                 * bytes: 0c c1 XX YY M1 M2 M3 M4 M5 M6 R4 R3 R2 R1 S2 S1
                 *
                 * XX always 81
                 * YY always 00
                 * M1-M6 is the MAC address
                 * R1-R4 is the transmit rate
                 * S1-S2 is the transmit status
                 */

                struct sk_buff *skb;
                u32 phy = le32_to_cpu(cmd->tx_status.rate);
                u32 q = (phy & AR9170_TX_PHY_QOS_MASK) >>
                        AR9170_TX_PHY_QOS_SHIFT;
#ifdef AR9170_QUEUE_DEBUG
                wiphy_debug(ar->hw->wiphy,
                            "recv tx_status for %pm, p:%08x, q:%d\n",
                            cmd->tx_status.dst, phy, q);
#endif /* AR9170_QUEUE_DEBUG */

                skb = ar9170_get_queued_skb(ar, cmd->tx_status.dst,
                                            &ar->tx_status[q],
                                            AR9170_TX_INVALID_RATE);
                if (unlikely(!skb))
                        return ;

                ar9170_tx_status(ar, skb, le16_to_cpu(cmd->tx_status.status));
                break;
                }

        case 0xc0:
                /*
                 * pre-TBTT event
                 */
                if (ar->vif && ar->vif->type == NL80211_IFTYPE_AP)
                        ieee80211_queue_work(ar->hw, &ar->beacon_work);
                break;

        case 0xc2:
                /*
                 * (IBSS) beacon send notification
                 * bytes: 04 c2 XX YY B4 B3 B2 B1
                 *
                 * XX always 80
                 * YY always 00
                 * B1-B4 "should" be the number of send out beacons.
                 */
                break;

        case 0xc3:
                /* End of Atim Window */
                break;

        case 0xc4:
                /* BlockACK bitmap */
                break;

        case 0xc5:
                /* BlockACK events */
                break;

        case 0xc6:
                /* Watchdog Interrupt */
                break;

        case 0xc9:
                /* retransmission issue / SIFS/EIFS collision ?! */
                break;

        /* firmware debug */
        case 0xca:
                printk(KERN_DEBUG "ar9170 FW: %.*s\n", len - 4,
                                (char *)buf + 4);
                break;
        case 0xcb:
                len -= 4;

                switch (len) {
                case 1:
                        printk(KERN_DEBUG "ar9170 FW: u8: %#.2x\n",
                                *((char *)buf + 4));
                        break;
                case 2:
                        printk(KERN_DEBUG "ar9170 FW: u8: %#.4x\n",
                                le16_to_cpup((__le16 *)((char *)buf + 4)));
                        break;
                case 4:
                        printk(KERN_DEBUG "ar9170 FW: u8: %#.8x\n",
                                le32_to_cpup((__le32 *)((char *)buf + 4)));
                        break;
                case 8:
                        printk(KERN_DEBUG "ar9170 FW: u8: %#.16lx\n",
                                (unsigned long)le64_to_cpup(
                                                (__le64 *)((char *)buf + 4)));
                        break;
                }
                break;
        case 0xcc:
                print_hex_dump_bytes("ar9170 FW:", DUMP_PREFIX_NONE,
                                     (char *)buf + 4, len - 4);
                break;

        default:
                pr_info("received unhandled event %x\n", cmd->type);
                print_hex_dump_bytes("dump:", DUMP_PREFIX_NONE, buf, len);
                break;
        }
}

static void ar9170_rx_reset_rx_mpdu(struct ar9170 *ar)
{
        memset(&ar->rx_mpdu.plcp, 0, sizeof(struct ar9170_rx_head));
        ar->rx_mpdu.has_plcp = false;
}

int ar9170_nag_limiter(struct ar9170 *ar)
{
        bool print_message;

        /*
         * we expect all sorts of errors in promiscuous mode.
         * don't bother with it, it's OK!
         */
        if (ar->sniffer_enabled)
                return false;

        /*
         * only go for frequent errors! The hardware tends to
         * do some stupid thing once in a while under load, in
         * noisy environments or just for fun!
         */
        if (time_before(jiffies, ar->bad_hw_nagger) && net_ratelimit())
                print_message = true;
        else
                print_message = false;

        /* reset threshold for "once in a while" */
        ar->bad_hw_nagger = jiffies + HZ / 4;
        return print_message;
}

static int ar9170_rx_mac_status(struct ar9170 *ar,
                                struct ar9170_rx_head *head,
                                struct ar9170_rx_macstatus *mac,
                                struct ieee80211_rx_status *status)
{
        u8 error, decrypt;

        BUILD_BUG_ON(sizeof(struct ar9170_rx_head) != 12);
        BUILD_BUG_ON(sizeof(struct ar9170_rx_macstatus) != 4);

        error = mac->error;
        if (error & AR9170_RX_ERROR_MMIC) {
                status->flag |= RX_FLAG_MMIC_ERROR;
                error &= ~AR9170_RX_ERROR_MMIC;
        }

        if (error & AR9170_RX_ERROR_PLCP) {
                status->flag |= RX_FLAG_FAILED_PLCP_CRC;
                error &= ~AR9170_RX_ERROR_PLCP;

                if (!(ar->filter_state & FIF_PLCPFAIL))
                        return -EINVAL;
        }

        if (error & AR9170_RX_ERROR_FCS) {
                status->flag |= RX_FLAG_FAILED_FCS_CRC;
                error &= ~AR9170_RX_ERROR_FCS;

                if (!(ar->filter_state & FIF_FCSFAIL))
                        return -EINVAL;
        }

        decrypt = ar9170_get_decrypt_type(mac);
        if (!(decrypt & AR9170_RX_ENC_SOFTWARE) &&
            decrypt != AR9170_ENC_ALG_NONE)
                status->flag |= RX_FLAG_DECRYPTED;

        /* ignore wrong RA errors */
        error &= ~AR9170_RX_ERROR_WRONG_RA;

        if (error & AR9170_RX_ERROR_DECRYPT) {
                error &= ~AR9170_RX_ERROR_DECRYPT;
                /*
                 * Rx decryption is done in place,
                 * the original data is lost anyway.
                 */

                return -EINVAL;
        }

        /* drop any other error frames */
        if (unlikely(error)) {
                /* TODO: update netdevice's RX dropped/errors statistics */

                if (ar9170_nag_limiter(ar))
                        wiphy_debug(ar->hw->wiphy,
                                    "received frame with suspicious error code (%#x).\n",
                                    error);

                return -EINVAL;
        }

        status->band = ar->channel->band;
        status->freq = ar->channel->center_freq;

        switch (mac->status & AR9170_RX_STATUS_MODULATION_MASK) {
        case AR9170_RX_STATUS_MODULATION_CCK:
                if (mac->status & AR9170_RX_STATUS_SHORT_PREAMBLE)
                        status->flag |= RX_FLAG_SHORTPRE;
                switch (head->plcp[0]) {
                case 0x0a:
                        status->rate_idx = 0;
                        break;
                case 0x14:
                        status->rate_idx = 1;
                        break;
                case 0x37:
                        status->rate_idx = 2;
                        break;
                case 0x6e:
                        status->rate_idx = 3;
                        break;
                default:
                        if (ar9170_nag_limiter(ar))
                                wiphy_err(ar->hw->wiphy,
                                          "invalid plcp cck rate (%x).\n",
                                          head->plcp[0]);
                        return -EINVAL;
                }
                break;

        case AR9170_RX_STATUS_MODULATION_DUPOFDM:
        case AR9170_RX_STATUS_MODULATION_OFDM:
                switch (head->plcp[0] & 0xf) {
                case 0xb:
                        status->rate_idx = 0;
                        break;
                case 0xf:
                        status->rate_idx = 1;
                        break;
                case 0xa:
                        status->rate_idx = 2;
                        break;
                case 0xe:
                        status->rate_idx = 3;
                        break;
                case 0x9:
                        status->rate_idx = 4;
                        break;
                case 0xd:
                        status->rate_idx = 5;
                        break;
                case 0x8:
                        status->rate_idx = 6;
                        break;
                case 0xc:
                        status->rate_idx = 7;
                        break;
                default:
                        if (ar9170_nag_limiter(ar))
                                wiphy_err(ar->hw->wiphy,
                                          "invalid plcp ofdm rate (%x).\n",
                                          head->plcp[0]);
                        return -EINVAL;
                }
                if (status->band == IEEE80211_BAND_2GHZ)
                        status->rate_idx += 4;
                break;

        case AR9170_RX_STATUS_MODULATION_HT:
                if (head->plcp[3] & 0x80)
                        status->flag |= RX_FLAG_40MHZ;
                if (head->plcp[6] & 0x80)
                        status->flag |= RX_FLAG_SHORT_GI;

                status->rate_idx = clamp(0, 75, head->plcp[6] & 0x7f);
                status->flag |= RX_FLAG_HT;
                break;

        default:
                if (ar9170_nag_limiter(ar))
                        wiphy_err(ar->hw->wiphy, "invalid modulation\n");
                return -EINVAL;
        }

        return 0;
}

static void ar9170_rx_phy_status(struct ar9170 *ar,
                                 struct ar9170_rx_phystatus *phy,
                                 struct ieee80211_rx_status *status)
{
        int i;

        BUILD_BUG_ON(sizeof(struct ar9170_rx_phystatus) != 20);

        for (i = 0; i < 3; i++)
                if (phy->rssi[i] != 0x80)
                        status->antenna |= BIT(i);

        /* post-process RSSI */
        for (i = 0; i < 7; i++)
                if (phy->rssi[i] & 0x80)
                        phy->rssi[i] = ((phy->rssi[i] & 0x7f) + 1) & 0x7f;

        /* TODO: we could do something with phy_errors */
        status->signal = ar->noise[0] + phy->rssi_combined;
}

static struct sk_buff *ar9170_rx_copy_data(u8 *buf, int len)
{
        struct sk_buff *skb;
        int reserved = 0;
        struct ieee80211_hdr *hdr = (void *) buf;

        if (ieee80211_is_data_qos(hdr->frame_control)) {
                u8 *qc = ieee80211_get_qos_ctl(hdr);
                reserved += NET_IP_ALIGN;

                if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
                        reserved += NET_IP_ALIGN;
        }

        if (ieee80211_has_a4(hdr->frame_control))
                reserved += NET_IP_ALIGN;

        reserved = 32 + (reserved & NET_IP_ALIGN);

        skb = dev_alloc_skb(len + reserved);
        if (likely(skb)) {
                skb_reserve(skb, reserved);
                memcpy(skb_put(skb, len), buf, len);
        }

        return skb;
}

/*
 * If the frame alignment is right (or the kernel has
 * CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS), and there
 * is only a single MPDU in the USB frame, then we could
 * submit to mac80211 the SKB directly. However, since
 * there may be multiple packets in one SKB in stream
 * mode, and we need to observe the proper ordering,
 * this is non-trivial.
 */

static void ar9170_handle_mpdu(struct ar9170 *ar, u8 *buf, int len)
{
        struct ar9170_rx_head *head;
        struct ar9170_rx_macstatus *mac;
        struct ar9170_rx_phystatus *phy = NULL;
        struct ieee80211_rx_status status;
        struct sk_buff *skb;
        int mpdu_len;

        if (unlikely(!IS_STARTED(ar) || len < (sizeof(*mac))))
                return ;

        /* Received MPDU */
        mpdu_len = len - sizeof(*mac);

        mac = (void *)(buf + mpdu_len);
        if (unlikely(mac->error & AR9170_RX_ERROR_FATAL)) {
                /* this frame is too damaged and can't be used - drop it */

                return ;
        }

        switch (mac->status & AR9170_RX_STATUS_MPDU_MASK) {
        case AR9170_RX_STATUS_MPDU_FIRST:
                /* first mpdu packet has the plcp header */
                if (likely(mpdu_len >= sizeof(struct ar9170_rx_head))) {
                        head = (void *) buf;
                        memcpy(&ar->rx_mpdu.plcp, (void *) buf,
                               sizeof(struct ar9170_rx_head));

                        mpdu_len -= sizeof(struct ar9170_rx_head);
                        buf += sizeof(struct ar9170_rx_head);
                        ar->rx_mpdu.has_plcp = true;
                } else {
                        if (ar9170_nag_limiter(ar))
                                wiphy_err(ar->hw->wiphy,
                                          "plcp info is clipped.\n");
                        return ;
                }
                break;

        case AR9170_RX_STATUS_MPDU_LAST:
                /* last mpdu has a extra tail with phy status information */

                if (likely(mpdu_len >= sizeof(struct ar9170_rx_phystatus))) {
                        mpdu_len -= sizeof(struct ar9170_rx_phystatus);
                        phy = (void *)(buf + mpdu_len);
                } else {
                        if (ar9170_nag_limiter(ar))
                                wiphy_err(ar->hw->wiphy,
                                          "frame tail is clipped.\n");
                        return ;
                }

        case AR9170_RX_STATUS_MPDU_MIDDLE:
                /* middle mpdus are just data */
                if (unlikely(!ar->rx_mpdu.has_plcp)) {
                        if (!ar9170_nag_limiter(ar))
                                return ;

                        wiphy_err(ar->hw->wiphy,
                                  "rx stream did not start with a first_mpdu frame tag.\n");

                        return ;
                }

                head = &ar->rx_mpdu.plcp;
                break;

        case AR9170_RX_STATUS_MPDU_SINGLE:
                /* single mpdu - has plcp (head) and phy status (tail) */
                head = (void *) buf;

                mpdu_len -= sizeof(struct ar9170_rx_head);
                mpdu_len -= sizeof(struct ar9170_rx_phystatus);

                buf += sizeof(struct ar9170_rx_head);
                phy = (void *)(buf + mpdu_len);
                break;

        default:
                BUG_ON(1);
                break;
        }

        if (unlikely(mpdu_len < FCS_LEN))
                return ;

        memset(&status, 0, sizeof(status));
        if (unlikely(ar9170_rx_mac_status(ar, head, mac, &status)))
                return ;

        if (phy)
                ar9170_rx_phy_status(ar, phy, &status);

        skb = ar9170_rx_copy_data(buf, mpdu_len);
        if (likely(skb)) {
                memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
                ieee80211_rx_irqsafe(ar->hw, skb);
        }
}

void ar9170_rx(struct ar9170 *ar, struct sk_buff *skb)
{
        unsigned int i, tlen, resplen, wlen = 0, clen = 0;
        u8 *tbuf, *respbuf;

        tbuf = skb->data;
        tlen = skb->len;

        while (tlen >= 4) {
                clen = tbuf[1] << 8 | tbuf[0];
                wlen = ALIGN(clen, 4);

                /* check if this is stream has a valid tag.*/
                if (tbuf[2] != 0 || tbuf[3] != 0x4e) {
                        /*
                         * TODO: handle the highly unlikely event that the
                         * corrupted stream has the TAG at the right position.
                         */

                        /* check if the frame can be repaired. */
                        if (!ar->rx_failover_missing) {
                                /* this is no "short read". */
                                if (ar9170_nag_limiter(ar)) {
                                        wiphy_err(ar->hw->wiphy,
                                                  "missing tag!\n");
                                        goto err_telluser;
                                } else
                                        goto err_silent;
                        }

                        if (ar->rx_failover_missing > tlen) {
                                if (ar9170_nag_limiter(ar)) {
                                        wiphy_err(ar->hw->wiphy,
                                                  "possible multi stream corruption!\n");
                                        goto err_telluser;
                                } else
                                        goto err_silent;
                        }

                        memcpy(skb_put(ar->rx_failover, tlen), tbuf, tlen);
                        ar->rx_failover_missing -= tlen;

                        if (ar->rx_failover_missing <= 0) {
                                /*
                                 * nested ar9170_rx call!
                                 * termination is guranteed, even when the
                                 * combined frame also have a element with
                                 * a bad tag.
                                 */

                                ar->rx_failover_missing = 0;
                                ar9170_rx(ar, ar->rx_failover);

                                skb_reset_tail_pointer(ar->rx_failover);
                                skb_trim(ar->rx_failover, 0);
                        }

                        return ;
                }

                /* check if stream is clipped */
                if (wlen > tlen - 4) {
                        if (ar->rx_failover_missing) {
                                /* TODO: handle double stream corruption. */
                                if (ar9170_nag_limiter(ar)) {
                                        wiphy_err(ar->hw->wiphy,
                                                  "double rx stream corruption!\n");
                                        goto err_telluser;
                                } else

                                        goto err_silent;
                        }

                        /*
                         * save incomplete data set.
                         * the firmware will resend the missing bits when
                         * the rx - descriptor comes round again.
                         */

                        memcpy(skb_put(ar->rx_failover, tlen), tbuf, tlen);
                        ar->rx_failover_missing = clen - tlen;
                        return ;
                }
                resplen = clen;
                respbuf = tbuf + 4;
                tbuf += wlen + 4;
                tlen -= wlen + 4;

                i = 0;

                /* weird thing, but this is the same in the original driver */
                while (resplen > 2 && i < 12 &&
                       respbuf[0] == 0xff && respbuf[1] == 0xff) {
                        i += 2;
                        resplen -= 2;
                        respbuf += 2;
                }

                if (resplen < 4)
                        continue;

                /* found the 6 * 0xffff marker? */
                if (i == 12)
                        ar9170_handle_command_response(ar, respbuf, resplen);
                else
                        ar9170_handle_mpdu(ar, respbuf, clen);
        }

        if (tlen) {
                if (net_ratelimit())
                        wiphy_err(ar->hw->wiphy,
                                  "%d bytes of unprocessed data left in rx stream!\n",
                                  tlen);

                goto err_telluser;
        }

        return ;

err_telluser:
        wiphy_err(ar->hw->wiphy,
                  "damaged RX stream data [want:%d, data:%d, rx:%d, pending:%d ]\n",
                  clen, wlen, tlen, ar->rx_failover_missing);

        if (ar->rx_failover_missing)
                print_hex_dump_bytes("rxbuf:", DUMP_PREFIX_OFFSET,
                                     ar->rx_failover->data,
                                     ar->rx_failover->len);

        print_hex_dump_bytes("stream:", DUMP_PREFIX_OFFSET,
                             skb->data, skb->len);

        wiphy_err(ar->hw->wiphy,
                  "If you see this message frequently, please check your hardware and cables.\n");

err_silent:
        if (ar->rx_failover_missing) {
                skb_reset_tail_pointer(ar->rx_failover);
                skb_trim(ar->rx_failover, 0);
                ar->rx_failover_missing = 0;
        }
}

#define AR9170_FILL_QUEUE(queue, ai_fs, cwmin, cwmax, _txop)            \
do {                                                                    \
        queue.aifs = ai_fs;                                             \
        queue.cw_min = cwmin;                                           \
        queue.cw_max = cwmax;                                           \
        queue.txop = _txop;                                             \
} while (0)

static int ar9170_op_start(struct ieee80211_hw *hw)
{
        struct ar9170 *ar = hw->priv;
        int err, i;

        mutex_lock(&ar->mutex);

        /* reinitialize queues statistics */
        memset(&ar->tx_stats, 0, sizeof(ar->tx_stats));
        for (i = 0; i < __AR9170_NUM_TXQ; i++)
                ar->tx_stats[i].limit = AR9170_TXQ_DEPTH;

        /* reset QoS defaults */
        AR9170_FILL_QUEUE(ar->edcf[0], 3, 15, 1023,  0); /* BEST EFFORT*/
        AR9170_FILL_QUEUE(ar->edcf[1], 7, 15, 1023,  0); /* BACKGROUND */
        AR9170_FILL_QUEUE(ar->edcf[2], 2, 7,    15, 94); /* VIDEO */
        AR9170_FILL_QUEUE(ar->edcf[3], 2, 3,     7, 47); /* VOICE */
        AR9170_FILL_QUEUE(ar->edcf[4], 2, 3,     7,  0); /* SPECIAL */

        /* set sane AMPDU defaults */
        ar->global_ampdu_density = 6;
        ar->global_ampdu_factor = 3;

        ar->bad_hw_nagger = jiffies;

        err = ar->open(ar);
        if (err)
                goto out;

        err = ar9170_init_mac(ar);
        if (err)
                goto out;

        err = ar9170_set_qos(ar);
        if (err)
                goto out;

        err = ar9170_init_phy(ar, IEEE80211_BAND_2GHZ);
        if (err)
                goto out;

        err = ar9170_init_rf(ar);
        if (err)
                goto out;

        /* start DMA */
        err = ar9170_write_reg(ar, 0x1c3d30, 0x100);
        if (err)
                goto out;

        ar->state = AR9170_STARTED;

out:
        mutex_unlock(&ar->mutex);
        return err;
}

static void ar9170_op_stop(struct ieee80211_hw *hw)
{
        struct ar9170 *ar = hw->priv;
        unsigned int i;

        if (IS_STARTED(ar))
                ar->state = AR9170_IDLE;

        cancel_delayed_work_sync(&ar->tx_janitor);
#ifdef CONFIG_AR9170_LEDS
        cancel_delayed_work_sync(&ar->led_work);
#endif
        cancel_work_sync(&ar->beacon_work);

        mutex_lock(&ar->mutex);

        if (IS_ACCEPTING_CMD(ar)) {
                ar9170_set_leds_state(ar, 0);

                /* stop DMA */
                ar9170_write_reg(ar, 0x1c3d30, 0);
                ar->stop(ar);
        }

        for (i = 0; i < __AR9170_NUM_TXQ; i++) {
                skb_queue_purge(&ar->tx_pending[i]);
                skb_queue_purge(&ar->tx_status[i]);
        }

        mutex_unlock(&ar->mutex);
}

static int ar9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
{
        struct ieee80211_hdr *hdr;
        struct ar9170_tx_control *txc;
        struct ieee80211_tx_info *info;
        struct ieee80211_tx_rate *txrate;
        struct ar9170_tx_info *arinfo;
        unsigned int queue = skb_get_queue_mapping(skb);
        u16 keytype = 0;
        u16 len, icv = 0;

        BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));

        hdr = (void *)skb->data;
        info = IEEE80211_SKB_CB(skb);
        len = skb->len;

        txc = (void *)skb_push(skb, sizeof(*txc));

        if (info->control.hw_key) {
                icv = info->control.hw_key->icv_len;

                switch (info->control.hw_key->cipher) {
                case WLAN_CIPHER_SUITE_WEP40:
                case WLAN_CIPHER_SUITE_WEP104:
                case WLAN_CIPHER_SUITE_TKIP:
                        keytype = AR9170_TX_MAC_ENCR_RC4;
                        break;
                case WLAN_CIPHER_SUITE_CCMP:
                        keytype = AR9170_TX_MAC_ENCR_AES;
                        break;
                default:
                        WARN_ON(1);
                        goto err_out;
                }
        }

        /* Length */
        txc->length = cpu_to_le16(len + icv + 4);

        txc->mac_control = cpu_to_le16(AR9170_TX_MAC_HW_DURATION |
                                       AR9170_TX_MAC_BACKOFF);
        txc->mac_control |= cpu_to_le16(ar9170_qos_hwmap[queue] <<
                                        AR9170_TX_MAC_QOS_SHIFT);
        txc->mac_control |= cpu_to_le16(keytype);
        txc->phy_control = cpu_to_le32(0);

        if (info->flags & IEEE80211_TX_CTL_NO_ACK)
                txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_NO_ACK);

        txrate = &info->control.rates[0];
        if (txrate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
                txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
        else if (txrate->flags & IEEE80211_TX_RC_USE_RTS_CTS)
                txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);

        arinfo = (void *)info->rate_driver_data;
        arinfo->timeout = jiffies + msecs_to_jiffies(AR9170_QUEUE_TIMEOUT);

        if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
             (is_valid_ether_addr(ieee80211_get_DA(hdr)))) {
                /*
                 * WARNING:
                 * Putting the QoS queue bits into an unexplored territory is
                 * certainly not elegant.
                 *
                 * In my defense: This idea provides a reasonable way to
                 * smuggle valuable information to the tx_status callback.
                 * Also, the idea behind this bit-abuse came straight from
                 * the original driver code.
                 */

                txc->phy_control |=
                        cpu_to_le32(queue << AR9170_TX_PHY_QOS_SHIFT);

                txc->mac_control |= cpu_to_le16(AR9170_TX_MAC_RATE_PROBE);
        }

        return 0;

err_out:
        skb_pull(skb, sizeof(*txc));
        return -EINVAL;
}

static void ar9170_tx_prepare_phy(struct ar9170 *ar, struct sk_buff *skb)
{
        struct ar9170_tx_control *txc;
        struct ieee80211_tx_info *info;
        struct ieee80211_rate *rate = NULL;
        struct ieee80211_tx_rate *txrate;
        u32 power, chains;

        txc = (void *) skb->data;
        info = IEEE80211_SKB_CB(skb);
        txrate = &info->control.rates[0];

        if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_GREENFIELD);

        if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_SHORT_PREAMBLE);

        if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ);
        /* this works because 40 MHz is 2 and dup is 3 */
        if (txrate->flags & IEEE80211_TX_RC_DUP_DATA)
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ_DUP);

        if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_SHORT_GI);

        if (txrate->flags & IEEE80211_TX_RC_MCS) {
                u32 r = txrate->idx;
                u8 *txpower;

                /* heavy clip control */
                txc->phy_control |= cpu_to_le32((r & 0x7) << 7);

                r <<= AR9170_TX_PHY_MCS_SHIFT;
                BUG_ON(r & ~AR9170_TX_PHY_MCS_MASK);

                txc->phy_control |= cpu_to_le32(r & AR9170_TX_PHY_MCS_MASK);
                txc->phy_control |= cpu_to_le32(AR9170_TX_PHY_MOD_HT);

                if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
                        if (info->band == IEEE80211_BAND_5GHZ)
                                txpower = ar->power_5G_ht40;
                        else
                                txpower = ar->power_2G_ht40;
                } else {
                        if (info->band == IEEE80211_BAND_5GHZ)
                                txpower = ar->power_5G_ht20;
                        else
                                txpower = ar->power_2G_ht20;
                }

                power = txpower[(txrate->idx) & 7];
        } else {
                u8 *txpower;
                u32 mod;
                u32 phyrate;
                u8 idx = txrate->idx;

                if (info->band != IEEE80211_BAND_2GHZ) {
                        idx += 4;
                        txpower = ar->power_5G_leg;
                        mod = AR9170_TX_PHY_MOD_OFDM;
                } else {
                        if (idx < 4) {
                                txpower = ar->power_2G_cck;
                                mod = AR9170_TX_PHY_MOD_CCK;
                        } else {
                                mod = AR9170_TX_PHY_MOD_OFDM;
                                txpower = ar->power_2G_ofdm;
                        }
                }

                rate = &__ar9170_ratetable[idx];

                phyrate = rate->hw_value & 0xF;
                power = txpower[(rate->hw_value & 0x30) >> 4];
                phyrate <<= AR9170_TX_PHY_MCS_SHIFT;

                txc->phy_control |= cpu_to_le32(mod);
                txc->phy_control |= cpu_to_le32(phyrate);
        }

        power <<= AR9170_TX_PHY_TX_PWR_SHIFT;
        power &= AR9170_TX_PHY_TX_PWR_MASK;
        txc->phy_control |= cpu_to_le32(power);

        /* set TX chains */
        if (ar->eeprom.tx_mask == 1) {
                chains = AR9170_TX_PHY_TXCHAIN_1;
        } else {
                chains = AR9170_TX_PHY_TXCHAIN_2;

                /* >= 36M legacy OFDM - use only one chain */
                if (rate && rate->bitrate >= 360)
                        chains = AR9170_TX_PHY_TXCHAIN_1;
        }
        txc->phy_control |= cpu_to_le32(chains << AR9170_TX_PHY_TXCHAIN_SHIFT);
}

static void ar9170_tx(struct ar9170 *ar)
{
        struct sk_buff *skb;
        unsigned long flags;
        struct ieee80211_tx_info *info;
        struct ar9170_tx_info *arinfo;
        unsigned int i, frames, frames_failed, remaining_space;
        int err;
        bool schedule_garbagecollector = false;

        BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));

        if (unlikely(!IS_STARTED(ar)))
                return ;

        remaining_space = AR9170_TX_MAX_PENDING;

        for (i = 0; i < __AR9170_NUM_TXQ; i++) {
                spin_lock_irqsave(&ar->tx_stats_lock, flags);
                frames = min(ar->tx_stats[i].limit - ar->tx_stats[i].len,
                             skb_queue_len(&ar->tx_pending[i]));

                if (remaining_space < frames) {
#ifdef AR9170_QUEUE_DEBUG
                        wiphy_debug(ar->hw->wiphy,
                                    "tx quota reached queue:%d, "
                                    "remaining slots:%d, needed:%d\n",
                                    i, remaining_space, frames);
#endif /* AR9170_QUEUE_DEBUG */
                        frames = remaining_space;
                }

                ar->tx_stats[i].len += frames;
                ar->tx_stats[i].count += frames;
                if (ar->tx_stats[i].len >= ar->tx_stats[i].limit) {
#ifdef AR9170_QUEUE_DEBUG
                        wiphy_debug(ar->hw->wiphy, "queue %d full\n", i);
                        wiphy_debug(ar->hw->wiphy, "stuck frames: ===>\n");
                        ar9170_dump_txqueue(ar, &ar->tx_pending[i]);
                        ar9170_dump_txqueue(ar, &ar->tx_status[i]);
#endif /* AR9170_QUEUE_DEBUG */

#ifdef AR9170_QUEUE_STOP_DEBUG
                        wiphy_debug(ar->hw->wiphy, "stop queue %d\n", i);
                        __ar9170_dump_txstats(ar);
#endif /* AR9170_QUEUE_STOP_DEBUG */
                        ieee80211_stop_queue(ar->hw, i);
                }

                spin_unlock_irqrestore(&ar->tx_stats_lock, flags);

                if (!frames)
                        continue;

                frames_failed = 0;
                while (frames) {
                        skb = skb_dequeue(&ar->tx_pending[i]);
                        if (unlikely(!skb)) {
                                frames_failed += frames;
                                frames = 0;
                                break;
                        }

                        info = IEEE80211_SKB_CB(skb);
                        arinfo = (void *) info->rate_driver_data;

                        /* TODO: cancel stuck frames */
                        arinfo->timeout = jiffies +
                                          msecs_to_jiffies(AR9170_TX_TIMEOUT);

#ifdef AR9170_QUEUE_DEBUG
                        wiphy_debug(ar->hw->wiphy, "send frame q:%d =>\n", i);
                        ar9170_print_txheader(ar, skb);
#endif /* AR9170_QUEUE_DEBUG */

                        err = ar->tx(ar, skb);
                        if (unlikely(err)) {
                                frames_failed++;
                                dev_kfree_skb_any(skb);
                        } else {
                                remaining_space--;
                                schedule_garbagecollector = true;
                        }

                        frames--;
                }

#ifdef AR9170_QUEUE_DEBUG
                wiphy_debug(ar->hw->wiphy,
                            "ar9170_tx report for queue %d\n", i);

                wiphy_debug(ar->hw->wiphy,
                            "unprocessed pending frames left:\n");
                ar9170_dump_txqueue(ar, &ar->tx_pending[i]);
#endif /* AR9170_QUEUE_DEBUG */

                if (unlikely(frames_failed)) {
#ifdef AR9170_QUEUE_DEBUG
                        wiphy_debug(ar->hw->wiphy,
                                    "frames failed %d =>\n", frames_failed);
#endif /* AR9170_QUEUE_DEBUG */

                        spin_lock_irqsave(&ar->tx_stats_lock, flags);
                        ar->tx_stats[i].len -= frames_failed;
                        ar->tx_stats[i].count -= frames_failed;
#ifdef AR9170_QUEUE_STOP_DEBUG
                        wiphy_debug(ar->hw->wiphy, "wake queue %d\n", i);
                        __ar9170_dump_txstats(ar);
#endif /* AR9170_QUEUE_STOP_DEBUG */
                        ieee80211_wake_queue(ar->hw, i);
                        spin_unlock_irqrestore(&ar->tx_stats_lock, flags);
                }
        }

        if (!schedule_garbagecollector)
                return;

        ieee80211_queue_delayed_work(ar->hw,
                                     &ar->tx_janitor,
                                     msecs_to_jiffies(AR9170_JANITOR_DELAY));
}

int ar9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
{
        struct ar9170 *ar = hw->priv;
        struct ieee80211_tx_info *info;
        unsigned int queue;

        if (unlikely(!IS_STARTED(ar)))
                goto err_free;

        if (unlikely(ar9170_tx_prepare(ar, skb)))
                goto err_free;

        queue = skb_get_queue_mapping(skb);
        info = IEEE80211_SKB_CB(skb);
        ar9170_tx_prepare_phy(ar, skb);
        skb_queue_tail(&ar->tx_pending[queue], skb);

        ar9170_tx(ar);
        return NETDEV_TX_OK;

err_free:
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
}

static int ar9170_op_add_interface(struct ieee80211_hw *hw,
                                   struct ieee80211_vif *vif)
{
        struct ar9170 *ar = hw->priv;
        struct ath_common *common = &ar->common;
        int err = 0;

        mutex_lock(&ar->mutex);

        if (ar->vif) {
                err = -EBUSY;
                goto unlock;
        }

        ar->vif = vif;
        memcpy(common->macaddr, vif->addr, ETH_ALEN);

        if (modparam_nohwcrypt || (ar->vif->type != NL80211_IFTYPE_STATION)) {
                ar->rx_software_decryption = true;
                ar->disable_offload = true;
        }

        ar->cur_filter = 0;
        err = ar9170_update_frame_filter(ar, AR9170_MAC_REG_FTF_DEFAULTS);
        if (err)
                goto unlock;

        err = ar9170_set_operating_mode(ar);

unlock:
        mutex_unlock(&ar->mutex);
        return err;
}

static void ar9170_op_remove_interface(struct ieee80211_hw *hw,
                                       struct ieee80211_vif *vif)
{
        struct ar9170 *ar = hw->priv;

        mutex_lock(&ar->mutex);
        ar->vif = NULL;
        ar9170_update_frame_filter(ar, 0);
        ar9170_set_beacon_timers(ar);
        dev_kfree_skb(ar->beacon);
        ar->beacon = NULL;
        ar->sniffer_enabled = false;
        ar->rx_software_decryption = false;
        ar9170_set_operating_mode(ar);
        mutex_unlock(&ar->mutex);
}

static int ar9170_op_config(struct ieee80211_hw *hw, u32 changed)
{
        struct ar9170 *ar = hw->priv;
        int err = 0;

        mutex_lock(&ar->mutex);

        if (changed & IEEE80211_CONF_CHANGE_LISTEN_INTERVAL) {
                /* TODO */
                err = 0;
        }

        if (changed & IEEE80211_CONF_CHANGE_PS) {
                /* TODO */
                err = 0;
        }

        if (changed & IEEE80211_CONF_CHANGE_POWER) {
                /* TODO */
                err = 0;
        }

        if (changed & IEEE80211_CONF_CHANGE_RETRY_LIMITS) {
                /*
                 * is it long_frame_max_tx_count or short_frame_max_tx_count?
                 */

                err = ar9170_set_hwretry_limit(ar,
                        ar->hw->conf.long_frame_max_tx_count);
                if (err)
                        goto out;
        }

        if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {

                /* adjust slot time for 5 GHz */
                err = ar9170_set_slot_time(ar);
                if (err)
                        goto out;

                err = ar9170_set_dyn_sifs_ack(ar);
                if (err)
                        goto out;

                err = ar9170_set_channel(ar, hw->conf.channel,
                                AR9170_RFI_NONE,
                                nl80211_to_ar9170(hw->conf.channel_type));
                if (err)
                        goto out;
        }

out:
        mutex_unlock(&ar->mutex);
        return err;
}

static u64 ar9170_op_prepare_multicast(struct ieee80211_hw *hw,
                                       struct netdev_hw_addr_list *mc_list)
{
        u64 mchash;
        struct netdev_hw_addr *ha;

        /* always get broadcast frames */
        mchash = 1ULL << (0xff >> 2);

        netdev_hw_addr_list_for_each(ha, mc_list)
                mchash |= 1ULL << (ha->addr[5] >> 2);

        return mchash;
}

static void ar9170_op_configure_filter(struct ieee80211_hw *hw,
                                       unsigned int changed_flags,
                                       unsigned int *new_flags,
                                       u64 multicast)
{
        struct ar9170 *ar = hw->priv;

        if (unlikely(!IS_ACCEPTING_CMD(ar)))
                return ;

        mutex_lock(&ar->mutex);

        /* mask supported flags */
        *new_flags &= FIF_ALLMULTI | FIF_CONTROL | FIF_BCN_PRBRESP_PROMISC |
                      FIF_PROMISC_IN_BSS | FIF_FCSFAIL | FIF_PLCPFAIL;
        ar->filter_state = *new_flags;
        /*
         * We can support more by setting the sniffer bit and
         * then checking the error flags, later.
         */

        if (changed_flags & FIF_ALLMULTI && *new_flags & FIF_ALLMULTI)
                multicast = ~0ULL;

        if (multicast != ar->cur_mc_hash)
                ar9170_update_multicast(ar, multicast);

        if (changed_flags & FIF_CONTROL) {
                u32 filter = AR9170_MAC_REG_FTF_PSPOLL |
                             AR9170_MAC_REG_FTF_RTS |
                             AR9170_MAC_REG_FTF_CTS |
                             AR9170_MAC_REG_FTF_ACK |
                             AR9170_MAC_REG_FTF_CFE |
                             AR9170_MAC_REG_FTF_CFE_ACK;

                if (*new_flags & FIF_CONTROL)
                        filter |= ar->cur_filter;
                else
                        filter &= (~ar->cur_filter);

                ar9170_update_frame_filter(ar, filter);
        }

        if (changed_flags & FIF_PROMISC_IN_BSS) {
                ar->sniffer_enabled = ((*new_flags) & FIF_PROMISC_IN_BSS) != 0;
                ar9170_set_operating_mode(ar);
        }

        mutex_unlock(&ar->mutex);
}


static void ar9170_op_bss_info_changed(struct ieee80211_hw *hw,
                                       struct ieee80211_vif *vif,
                                       struct ieee80211_bss_conf *bss_conf,
                                       u32 changed)
{
        struct ar9170 *ar = hw->priv;
        struct ath_common *common = &ar->common;
        int err = 0;

        mutex_lock(&ar->mutex);

        if (changed & BSS_CHANGED_BSSID) {
                memcpy(common->curbssid, bss_conf->bssid, ETH_ALEN);
                err = ar9170_set_operating_mode(ar);
                if (err)
                        goto out;
        }

        if (changed & BSS_CHANGED_BEACON_ENABLED)
                ar->enable_beacon = bss_conf->enable_beacon;

        if (changed & BSS_CHANGED_BEACON) {
                err = ar9170_update_beacon(ar);
                if (err)
                        goto out;
        }

        if (changed & (BSS_CHANGED_BEACON_ENABLED | BSS_CHANGED_BEACON |
                       BSS_CHANGED_BEACON_INT)) {
                err = ar9170_set_beacon_timers(ar);
                if (err)
                        goto out;
        }

        if (changed & BSS_CHANGED_ASSOC) {
#ifndef CONFIG_AR9170_LEDS
                /* enable assoc LED. */
                err = ar9170_set_leds_state(ar, bss_conf->assoc ? 2 : 0);
#endif /* CONFIG_AR9170_LEDS */
        }

        if (changed & BSS_CHANGED_HT) {
                /* TODO */
                err = 0;
        }

        if (changed & BSS_CHANGED_ERP_SLOT) {
                err = ar9170_set_slot_time(ar);
                if (err)
                        goto out;
        }

        if (changed & BSS_CHANGED_BASIC_RATES) {
                err = ar9170_set_basic_rates(ar);
                if (err)
                        goto out;
        }

out:
        mutex_unlock(&ar->mutex);
}

static u64 ar9170_op_get_tsf(struct ieee80211_hw *hw)
{
        struct ar9170 *ar = hw->priv;
        int err;
        u64 tsf;
#define NR 3
        static const u32 addr[NR] = { AR9170_MAC_REG_TSF_H,
                                    AR9170_MAC_REG_TSF_L,
                                    AR9170_MAC_REG_TSF_H };
        u32 val[NR];
        int loops = 0;

        mutex_lock(&ar->mutex);

        while (loops++ < 10) {
                err = ar9170_read_mreg(ar, NR, addr, val);
                if (err || val[0] == val[2])
                        break;
        }

        mutex_unlock(&ar->mutex);

        if (WARN_ON(err))
                return 0;
        tsf = val[0];
        tsf = (tsf << 32) | val[1];
        return tsf;
#undef NR
}

static int ar9170_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
                          struct ieee80211_vif *vif, struct ieee80211_sta *sta,
                          struct ieee80211_key_conf *key)
{
        struct ar9170 *ar = hw->priv;
        int err = 0, i;
        u8 ktype;

        if ((!ar->vif) || (ar->disable_offload))
                return -EOPNOTSUPP;

        switch (key->cipher) {
        case WLAN_CIPHER_SUITE_WEP40:
                ktype = AR9170_ENC_ALG_WEP64;
                break;
        case WLAN_CIPHER_SUITE_WEP104:
                ktype = AR9170_ENC_ALG_WEP128;
                break;
        case WLAN_CIPHER_SUITE_TKIP:
                ktype = AR9170_ENC_ALG_TKIP;
                break;
        case WLAN_CIPHER_SUITE_CCMP:
                ktype = AR9170_ENC_ALG_AESCCMP;
                break;
        default:
                return -EOPNOTSUPP;
        }

        mutex_lock(&ar->mutex);
        if (cmd == SET_KEY) {
                if (unlikely(!IS_STARTED(ar))) {
                        err = -EOPNOTSUPP;
                        goto out;
                }

                /* group keys need all-zeroes address */
                if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE))
                        sta = NULL;

                if (key->flags & IEEE80211_KEY_FLAG_PAIRWISE) {
                        for (i = 0; i < 64; i++)
                                if (!(ar->usedkeys & BIT(i)))
                                        break;
                        if (i == 64) {
                                ar->rx_software_decryption = true;
                                ar9170_set_operating_mode(ar);
                                err = -ENOSPC;
                                goto out;
                        }
                } else {
                        i = 64 + key->keyidx;
                }

                key->hw_key_idx = i;

                err = ar9170_upload_key(ar, i, sta ? sta->addr : NULL, ktype, 0,
                                        key->key, min_t(u8, 16, key->keylen));
                if (err)
                        goto out;

                if (key->cipher == WLAN_CIPHER_SUITE_TKIP) {
                        err = ar9170_upload_key(ar, i, sta ? sta->addr : NULL,
                                                ktype, 1, key->key + 16, 16);
                        if (err)
                                goto out;

                        /*
                         * hardware is not capable generating the MMIC
                         * for fragmented frames!
                         */
                        key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIC;
                }

                if (i < 64)
                        ar->usedkeys |= BIT(i);

                key->flags |= IEEE80211_KEY_FLAG_GENERATE_IV;
        } else {
                if (unlikely(!IS_STARTED(ar))) {
                        /* The device is gone... together with the key ;-) */
                        err = 0;
                        goto out;
                }

                err = ar9170_disable_key(ar, key->hw_key_idx);
                if (err)
                        goto out;

                if (key->hw_key_idx < 64) {
                        ar->usedkeys &= ~BIT(key->hw_key_idx);
                } else {
                        err = ar9170_upload_key(ar, key->hw_key_idx, NULL,
                                                AR9170_ENC_ALG_NONE, 0,
                                                NULL, 0);
                        if (err)
                                goto out;

                        if (key->cipher == WLAN_CIPHER_SUITE_TKIP) {
                                err = ar9170_upload_key(ar, key->hw_key_idx,
                                                        NULL,
                                                        AR9170_ENC_ALG_NONE, 1,
                                                        NULL, 0);
                                if (err)
                                        goto out;
                        }

                }
        }

        ar9170_regwrite_begin(ar);
        ar9170_regwrite(AR9170_MAC_REG_ROLL_CALL_TBL_L, ar->usedkeys);
        ar9170_regwrite(AR9170_MAC_REG_ROLL_CALL_TBL_H, ar->usedkeys >> 32);
        ar9170_regwrite_finish();
        err = ar9170_regwrite_result();

out:
        mutex_unlock(&ar->mutex);

        return err;
}

static int ar9170_get_stats(struct ieee80211_hw *hw,
                            struct ieee80211_low_level_stats *stats)
{
        struct ar9170 *ar = hw->priv;
        u32 val;
        int err;

        mutex_lock(&ar->mutex);
        err = ar9170_read_reg(ar, AR9170_MAC_REG_TX_RETRY, &val);
        ar->stats.dot11ACKFailureCount += val;

        memcpy(stats, &ar->stats, sizeof(*stats));
        mutex_unlock(&ar->mutex);

        return 0;
}

static int ar9170_get_survey(struct ieee80211_hw *hw, int idx,
                                struct survey_info *survey)
{
        struct ar9170 *ar = hw->priv;
        struct ieee80211_conf *conf = &hw->conf;

        if (idx != 0)
                return -ENOENT;

        /* TODO: update noise value, e.g. call ar9170_set_channel */

        survey->channel = conf->channel;
        survey->filled = SURVEY_INFO_NOISE_DBM;
        survey->noise = ar->noise[0];

        return 0;
}

static int ar9170_conf_tx(struct ieee80211_hw *hw, u16 queue,
                          const struct ieee80211_tx_queue_params *param)
{
        struct ar9170 *ar = hw->priv;
        int ret;

        mutex_lock(&ar->mutex);
        if (queue < __AR9170_NUM_TXQ) {
                memcpy(&ar->edcf[ar9170_qos_hwmap[queue]],
                       param, sizeof(*param));

                ret = ar9170_set_qos(ar);
        } else {
                ret = -EINVAL;
        }

        mutex_unlock(&ar->mutex);
        return ret;
}

static int ar9170_ampdu_action(struct ieee80211_hw *hw,
                               struct ieee80211_vif *vif,
                               enum ieee80211_ampdu_mlme_action action,
                               struct ieee80211_sta *sta, u16 tid, u16 *ssn)
{
        switch (action) {
        case IEEE80211_AMPDU_RX_START:
        case IEEE80211_AMPDU_RX_STOP:
                /* Handled by firmware */
                break;

        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

static const struct ieee80211_ops ar9170_ops = {
        .start                  = ar9170_op_start,
        .stop                   = ar9170_op_stop,
        .tx                     = ar9170_op_tx,
        .add_interface          = ar9170_op_add_interface,
        .remove_interface       = ar9170_op_remove_interface,
        .config                 = ar9170_op_config,
        .prepare_multicast      = ar9170_op_prepare_multicast,
        .configure_filter       = ar9170_op_configure_filter,
        .conf_tx                = ar9170_conf_tx,
        .bss_info_changed       = ar9170_op_bss_info_changed,
        .get_tsf                = ar9170_op_get_tsf,
        .set_key                = ar9170_set_key,
        .get_stats              = ar9170_get_stats,
        .get_survey             = ar9170_get_survey,
        .ampdu_action           = ar9170_ampdu_action,
};

void *ar9170_alloc(size_t priv_size)
{
        struct ieee80211_hw *hw;
        struct ar9170 *ar;
        struct sk_buff *skb;
        int i;

        /*
         * this buffer is used for rx stream reconstruction.
         * Under heavy load this device (or the transport layer?)
         * tends to split the streams into separate rx descriptors.
         */

        skb = __dev_alloc_skb(AR9170_RX_STREAM_MAX_SIZE, GFP_KERNEL);
        if (!skb)
                goto err_nomem;

        hw = ieee80211_alloc_hw(priv_size, &ar9170_ops);
        if (!hw)
                goto err_nomem;

        ar = hw->priv;
        ar->hw = hw;
        ar->rx_failover = skb;

        mutex_init(&ar->mutex);
        spin_lock_init(&ar->cmdlock);
        spin_lock_init(&ar->tx_stats_lock);
        for (i = 0; i < __AR9170_NUM_TXQ; i++) {
                skb_queue_head_init(&ar->tx_status[i]);
                skb_queue_head_init(&ar->tx_pending[i]);
        }
        ar9170_rx_reset_rx_mpdu(ar);
        INIT_WORK(&ar->beacon_work, ar9170_new_beacon);
        INIT_DELAYED_WORK(&ar->tx_janitor, ar9170_tx_janitor);

        /* all hw supports 2.4 GHz, so set channel to 1 by default */
        ar->channel = &ar9170_2ghz_chantable[0];

        /* first part of wiphy init */
        ar->hw->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION) |
                                         BIT(NL80211_IFTYPE_WDS) |
                                         BIT(NL80211_IFTYPE_ADHOC);
        ar->hw->flags |= IEEE80211_HW_RX_INCLUDES_FCS |
                         IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING |
                         IEEE80211_HW_SIGNAL_DBM;

        ar->hw->queues = __AR9170_NUM_TXQ;
        ar->hw->extra_tx_headroom = 8;

        ar->hw->max_rates = 1;
        ar->hw->max_rate_tries = 3;

        for (i = 0; i < ARRAY_SIZE(ar->noise); i++)
                ar->noise[i] = -95; /* ATH_DEFAULT_NOISE_FLOOR */

        return ar;

err_nomem:
        kfree_skb(skb);
        return ERR_PTR(-ENOMEM);
}

static int ar9170_read_eeprom(struct ar9170 *ar)
{
#define RW      8       /* number of words to read at once */
#define RB      (sizeof(u32) * RW)
        struct ath_regulatory *regulatory = &ar->common.regulatory;
        u8 *eeprom = (void *)&ar->eeprom;
        u8 *addr = ar->eeprom.mac_address;
        __le32 offsets[RW];
        unsigned int rx_streams, tx_streams, tx_params = 0;
        int i, j, err, bands = 0;

        BUILD_BUG_ON(sizeof(ar->eeprom) & 3);

        BUILD_BUG_ON(RB > AR9170_MAX_CMD_LEN - 4);
#ifndef __CHECKER__
        /* don't want to handle trailing remains */
        BUILD_BUG_ON(sizeof(ar->eeprom) % RB);
#endif

        for (i = 0; i < sizeof(ar->eeprom)/RB; i++) {
                for (j = 0; j < RW; j++)
                        offsets[j] = cpu_to_le32(AR9170_EEPROM_START +
                                                 RB * i + 4 * j);

                err = ar->exec_cmd(ar, AR9170_CMD_RREG,
                                   RB, (u8 *) &offsets,
                                   RB, eeprom + RB * i);
                if (err)
                        return err;
        }

#undef RW
#undef RB

        if (ar->eeprom.length == cpu_to_le16(0xFFFF))
                return -ENODATA;

        if (ar->eeprom.operating_flags & AR9170_OPFLAG_2GHZ) {
                ar->hw->wiphy->bands[IEEE80211_BAND_2GHZ] = &ar9170_band_2GHz;
                bands++;
        }
        if (ar->eeprom.operating_flags & AR9170_OPFLAG_5GHZ) {
                ar->hw->wiphy->bands[IEEE80211_BAND_5GHZ] = &ar9170_band_5GHz;
                bands++;
        }

        rx_streams = hweight8(ar->eeprom.rx_mask);
        tx_streams = hweight8(ar->eeprom.tx_mask);

        if (rx_streams != tx_streams)
                tx_params = IEEE80211_HT_MCS_TX_RX_DIFF;

        if (tx_streams >= 1 && tx_streams <= IEEE80211_HT_MCS_TX_MAX_STREAMS)
                tx_params = (tx_streams - 1) <<
                            IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT;

        ar9170_band_2GHz.ht_cap.mcs.tx_params |= tx_params;
        ar9170_band_5GHz.ht_cap.mcs.tx_params |= tx_params;

        /*
         * I measured this, a bandswitch takes roughly
         * 135 ms and a frequency switch about 80.
         *
         * FIXME: measure these values again once EEPROM settings
         *        are used, that will influence them!
         */
        if (bands == 2)
                ar->hw->channel_change_time = 135 * 1000;
        else
                ar->hw->channel_change_time = 80 * 1000;

        regulatory->current_rd = le16_to_cpu(ar->eeprom.reg_domain[0]);
        regulatory->current_rd_ext = le16_to_cpu(ar->eeprom.reg_domain[1]);

        /* second part of wiphy init */
        SET_IEEE80211_PERM_ADDR(ar->hw, addr);

        return bands ? 0 : -EINVAL;
}

static int ar9170_reg_notifier(struct wiphy *wiphy,
                        struct regulatory_request *request)
{
        struct ieee80211_hw *hw = wiphy_to_ieee80211_hw(wiphy);
        struct ar9170 *ar = hw->priv;

        return ath_reg_notifier_apply(wiphy, request, &ar->common.regulatory);
}

int ar9170_register(struct ar9170 *ar, struct device *pdev)
{
        struct ath_regulatory *regulatory = &ar->common.regulatory;
        int err;

        /* try to read EEPROM, init MAC addr */
        err = ar9170_read_eeprom(ar);
        if (err)
                goto err_out;

        err = ath_regd_init(regulatory, ar->hw->wiphy,
                            ar9170_reg_notifier);
        if (err)
                goto err_out;

        err = ieee80211_register_hw(ar->hw);
        if (err)
                goto err_out;

        if (!ath_is_world_regd(regulatory))
                regulatory_hint(ar->hw->wiphy, regulatory->alpha2);

        err = ar9170_init_leds(ar);
        if (err)
                goto err_unreg;

#ifdef CONFIG_AR9170_LEDS
        err = ar9170_register_leds(ar);
        if (err)
                goto err_unreg;
#endif /* CONFIG_AR9170_LEDS */

        dev_info(pdev, "Atheros AR9170 is registered as '%s'\n",
                 wiphy_name(ar->hw->wiphy));

        ar->registered = true;
        return 0;

err_unreg:
        ieee80211_unregister_hw(ar->hw);

err_out:
        return err;
}

void ar9170_unregister(struct ar9170 *ar)
{
        if (ar->registered) {
#ifdef CONFIG_AR9170_LEDS
                ar9170_unregister_leds(ar);
#endif /* CONFIG_AR9170_LEDS */

        ieee80211_unregister_hw(ar->hw);
        }

        kfree_skb(ar->rx_failover);
        mutex_destroy(&ar->mutex);
}