mac80211: clean up set_key callback

[linux-2.6/mini2440.git] / drivers / net / wireless / rt2x00 / rt2x00mac.c

/*
        Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
        <http://rt2x00.serialmonkey.com>

        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; if not, write to the
        Free Software Foundation, Inc.,
        59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
        Module: rt2x00mac
        Abstract: rt2x00 generic mac80211 routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

static int rt2x00mac_tx_rts_cts(struct rt2x00_dev *rt2x00dev,
                                struct data_queue *queue,
                                struct sk_buff *frag_skb)
{
        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(frag_skb);
        struct ieee80211_tx_info *rts_info;
        struct sk_buff *skb;
        unsigned int data_length;
        int retval = 0;

        if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
                data_length = sizeof(struct ieee80211_cts);
        else
                data_length = sizeof(struct ieee80211_rts);

        skb = dev_alloc_skb(data_length + rt2x00dev->hw->extra_tx_headroom);
        if (unlikely(!skb)) {
                WARNING(rt2x00dev, "Failed to create RTS/CTS frame.\n");
                return -ENOMEM;
        }

        skb_reserve(skb, rt2x00dev->hw->extra_tx_headroom);
        skb_put(skb, data_length);

        /*
         * Copy TX information over from original frame to
         * RTS/CTS frame. Note that we set the no encryption flag
         * since we don't want this frame to be encrypted.
         * RTS frames should be acked, while CTS-to-self frames
         * should not. The ready for TX flag is cleared to prevent
         * it being automatically send when the descriptor is
         * written to the hardware.
         */
        memcpy(skb->cb, frag_skb->cb, sizeof(skb->cb));
        rts_info = IEEE80211_SKB_CB(skb);
        rts_info->control.rates[0].flags &= ~IEEE80211_TX_RC_USE_RTS_CTS;
        rts_info->control.rates[0].flags &= ~IEEE80211_TX_RC_USE_CTS_PROTECT;
        rts_info->flags &= ~IEEE80211_TX_CTL_REQ_TX_STATUS;

        if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
                rts_info->flags |= IEEE80211_TX_CTL_NO_ACK;
        else
                rts_info->flags &= ~IEEE80211_TX_CTL_NO_ACK;

        skb->do_not_encrypt = 1;

        /*
         * RTS/CTS frame should use the length of the frame plus any
         * encryption overhead that will be added by the hardware.
         */
        data_length += rt2x00crypto_tx_overhead(rt2x00dev, skb);

        if (tx_info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
                ieee80211_ctstoself_get(rt2x00dev->hw, tx_info->control.vif,
                                        frag_skb->data, data_length, tx_info,
                                        (struct ieee80211_cts *)(skb->data));
        else
                ieee80211_rts_get(rt2x00dev->hw, tx_info->control.vif,
                                  frag_skb->data, data_length, tx_info,
                                  (struct ieee80211_rts *)(skb->data));

        retval = rt2x00queue_write_tx_frame(queue, skb);
        if (retval) {
                dev_kfree_skb_any(skb);
                WARNING(rt2x00dev, "Failed to send RTS/CTS frame.\n");
        }

        return retval;
}

int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
        struct ieee80211_hdr *ieee80211hdr = (struct ieee80211_hdr *)skb->data;
        enum data_queue_qid qid = skb_get_queue_mapping(skb);
        struct data_queue *queue;
        u16 frame_control;

        /*
         * Mac80211 might be calling this function while we are trying
         * to remove the device or perhaps suspending it.
         * Note that we can only stop the TX queues inside the TX path
         * due to possible race conditions in mac80211.
         */
        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                goto exit_fail;

        /*
         * Determine which queue to put packet on.
         */
        if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM &&
            test_bit(DRIVER_REQUIRE_ATIM_QUEUE, &rt2x00dev->flags))
                queue = rt2x00queue_get_queue(rt2x00dev, QID_ATIM);
        else
                queue = rt2x00queue_get_queue(rt2x00dev, qid);
        if (unlikely(!queue)) {
                ERROR(rt2x00dev,
                      "Attempt to send packet over invalid queue %d.\n"
                      "Please file bug report to %s.\n", qid, DRV_PROJECT);
                goto exit_fail;
        }

        /*
         * If CTS/RTS is required. create and queue that frame first.
         * Make sure we have at least enough entries available to send
         * this CTS/RTS frame as well as the data frame.
         * Note that when the driver has set the set_rts_threshold()
         * callback function it doesn't need software generation of
         * either RTS or CTS-to-self frame and handles everything
         * inside the hardware.
         */
        frame_control = le16_to_cpu(ieee80211hdr->frame_control);
        if ((tx_info->control.rates[0].flags & (IEEE80211_TX_RC_USE_RTS_CTS |
                                                IEEE80211_TX_RC_USE_CTS_PROTECT)) &&
            !rt2x00dev->ops->hw->set_rts_threshold) {
                if (rt2x00queue_available(queue) <= 1)
                        goto exit_fail;

                if (rt2x00mac_tx_rts_cts(rt2x00dev, queue, skb))
                        goto exit_fail;
        }

        if (rt2x00queue_write_tx_frame(queue, skb))
                goto exit_fail;

        if (rt2x00queue_threshold(queue))
                ieee80211_stop_queue(rt2x00dev->hw, qid);

        return NETDEV_TX_OK;

 exit_fail:
        ieee80211_stop_queue(rt2x00dev->hw, qid);
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
}
EXPORT_SYMBOL_GPL(rt2x00mac_tx);

int rt2x00mac_start(struct ieee80211_hw *hw)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;

        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return 0;

        return rt2x00lib_start(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00mac_start);

void rt2x00mac_stop(struct ieee80211_hw *hw)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;

        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return;

        rt2x00lib_stop(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00mac_stop);

int rt2x00mac_add_interface(struct ieee80211_hw *hw,
                            struct ieee80211_if_init_conf *conf)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct rt2x00_intf *intf = vif_to_intf(conf->vif);
        struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, QID_BEACON);
        struct queue_entry *entry = NULL;
        unsigned int i;

        /*
         * Don't allow interfaces to be added
         * the device has disappeared.
         */
        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
            !test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
                return -ENODEV;

        switch (conf->type) {
        case NL80211_IFTYPE_AP:
                /*
                 * We don't support mixed combinations of
                 * sta and ap interfaces.
                 */
                if (rt2x00dev->intf_sta_count)
                        return -ENOBUFS;

                /*
                 * Check if we exceeded the maximum amount
                 * of supported interfaces.
                 */
                if (rt2x00dev->intf_ap_count >= rt2x00dev->ops->max_ap_intf)
                        return -ENOBUFS;

                break;
        case NL80211_IFTYPE_STATION:
        case NL80211_IFTYPE_ADHOC:
        case NL80211_IFTYPE_MESH_POINT:
        case NL80211_IFTYPE_WDS:
                /*
                 * We don't support mixed combinations of
                 * sta and ap interfaces.
                 */
                if (rt2x00dev->intf_ap_count)
                        return -ENOBUFS;

                /*
                 * Check if we exceeded the maximum amount
                 * of supported interfaces.
                 */
                if (rt2x00dev->intf_sta_count >= rt2x00dev->ops->max_sta_intf)
                        return -ENOBUFS;

                break;
        default:
                return -EINVAL;
        }

        /*
         * Loop through all beacon queues to find a free
         * entry. Since there are as much beacon entries
         * as the maximum interfaces, this search shouldn't
         * fail.
         */
        for (i = 0; i < queue->limit; i++) {
                entry = &queue->entries[i];
                if (!test_and_set_bit(ENTRY_BCN_ASSIGNED, &entry->flags))
                        break;
        }

        if (unlikely(i == queue->limit))
                return -ENOBUFS;

        /*
         * We are now absolutely sure the interface can be created,
         * increase interface count and start initialization.
         */

        if (conf->type == NL80211_IFTYPE_AP)
                rt2x00dev->intf_ap_count++;
        else
                rt2x00dev->intf_sta_count++;

        spin_lock_init(&intf->lock);
        spin_lock_init(&intf->seqlock);
        intf->beacon = entry;

        if (conf->type == NL80211_IFTYPE_AP)
                memcpy(&intf->bssid, conf->mac_addr, ETH_ALEN);
        memcpy(&intf->mac, conf->mac_addr, ETH_ALEN);

        /*
         * The MAC adddress must be configured after the device
         * has been initialized. Otherwise the device can reset
         * the MAC registers.
         */
        rt2x00lib_config_intf(rt2x00dev, intf, conf->type, intf->mac, NULL);

        /*
         * Some filters depend on the current working mode. We can force
         * an update during the next configure_filter() run by mac80211 by
         * resetting the current packet_filter state.
         */
        rt2x00dev->packet_filter = 0;

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_add_interface);

void rt2x00mac_remove_interface(struct ieee80211_hw *hw,
                                struct ieee80211_if_init_conf *conf)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct rt2x00_intf *intf = vif_to_intf(conf->vif);

        /*
         * Don't allow interfaces to be remove while
         * either the device has disappeared or when
         * no interface is present.
         */
        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
            (conf->type == NL80211_IFTYPE_AP && !rt2x00dev->intf_ap_count) ||
            (conf->type != NL80211_IFTYPE_AP && !rt2x00dev->intf_sta_count))
                return;

        if (conf->type == NL80211_IFTYPE_AP)
                rt2x00dev->intf_ap_count--;
        else
                rt2x00dev->intf_sta_count--;

        /*
         * Release beacon entry so it is available for
         * new interfaces again.
         */
        clear_bit(ENTRY_BCN_ASSIGNED, &intf->beacon->flags);

        /*
         * Make sure the bssid and mac address registers
         * are cleared to prevent false ACKing of frames.
         */
        rt2x00lib_config_intf(rt2x00dev, intf,
                              NL80211_IFTYPE_UNSPECIFIED, NULL, NULL);
}
EXPORT_SYMBOL_GPL(rt2x00mac_remove_interface);

int rt2x00mac_config(struct ieee80211_hw *hw, u32 changed)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct ieee80211_conf *conf = &hw->conf;
        int status;

        /*
         * Mac80211 might be calling this function while we are trying
         * to remove the device or perhaps suspending it.
         */
        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return 0;

        /*
         * Only change device state when the radio is enabled. It does not
         * matter what parameters we have configured when the radio is disabled
         * because we won't be able to send or receive anyway. Also note that
         * some configuration parameters (e.g. channel and antenna values) can
         * only be set when the radio is enabled.
         */
        if (conf->radio_enabled) {
                /* For programming the values, we have to turn RX off */
                rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF);

                /* Enable the radio */
                status = rt2x00lib_enable_radio(rt2x00dev);
                if (unlikely(status))
                        return status;

                /*
                 * When we've just turned on the radio, we want to reprogram
                 * everything to ensure a consistent state
                 */
                rt2x00lib_config(rt2x00dev, conf, changed);

                /*
                 * The radio was enabled, configure the antenna to the
                 * default settings, the link tuner will later start
                 * continue configuring the antenna based on the software
                 * diversity. But for non-diversity configurations, we need
                 * to have configured the correct state now.
                 */
                if (changed & IEEE80211_CONF_CHANGE_RADIO_ENABLED)
                        rt2x00lib_config_antenna(rt2x00dev,
                                                 &rt2x00dev->default_ant);

                /* Turn RX back on */
                rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON);
        } else {
                /* Disable the radio */
                rt2x00lib_disable_radio(rt2x00dev);
        }

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_config);

int rt2x00mac_config_interface(struct ieee80211_hw *hw,
                               struct ieee80211_vif *vif,
                               struct ieee80211_if_conf *conf)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct rt2x00_intf *intf = vif_to_intf(vif);
        int update_bssid = 0;
        int status = 0;

        /*
         * Mac80211 might be calling this function while we are trying
         * to remove the device or perhaps suspending it.
         */
        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return 0;

        spin_lock(&intf->lock);

        /*
         * conf->bssid can be NULL if coming from the internal
         * beacon update routine.
         */
        if (conf->changed & IEEE80211_IFCC_BSSID && conf->bssid) {
                update_bssid = 1;
                memcpy(&intf->bssid, conf->bssid, ETH_ALEN);
        }

        spin_unlock(&intf->lock);

        /*
         * Call rt2x00_config_intf() outside of the spinlock context since
         * the call will sleep for USB drivers. By using the ieee80211_if_conf
         * values as arguments we make keep access to rt2x00_intf thread safe
         * even without the lock.
         */
        rt2x00lib_config_intf(rt2x00dev, intf, vif->type, NULL,
                              update_bssid ? conf->bssid : NULL);

        /*
         * Update the beacon.
         */
        if (conf->changed & IEEE80211_IFCC_BEACON)
                status = rt2x00queue_update_beacon(rt2x00dev, vif);

        return status;
}
EXPORT_SYMBOL_GPL(rt2x00mac_config_interface);

void rt2x00mac_configure_filter(struct ieee80211_hw *hw,
                                unsigned int changed_flags,
                                unsigned int *total_flags,
                                int mc_count, struct dev_addr_list *mc_list)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;

        /*
         * Mask off any flags we are going to ignore
         * from the total_flags field.
         */
        *total_flags &=
            FIF_ALLMULTI |
            FIF_FCSFAIL |
            FIF_PLCPFAIL |
            FIF_CONTROL |
            FIF_OTHER_BSS |
            FIF_PROMISC_IN_BSS;

        /*
         * Apply some rules to the filters:
         * - Some filters imply different filters to be set.
         * - Some things we can't filter out at all.
         * - Multicast filter seems to kill broadcast traffic so never use it.
         */
        *total_flags |= FIF_ALLMULTI;
        if (*total_flags & FIF_OTHER_BSS ||
            *total_flags & FIF_PROMISC_IN_BSS)
                *total_flags |= FIF_PROMISC_IN_BSS | FIF_OTHER_BSS;

        /*
         * Check if there is any work left for us.
         */
        if (rt2x00dev->packet_filter == *total_flags)
                return;
        rt2x00dev->packet_filter = *total_flags;

        if (!test_bit(DRIVER_REQUIRE_SCHEDULED, &rt2x00dev->flags))
                rt2x00dev->ops->lib->config_filter(rt2x00dev, *total_flags);
        else
                queue_work(rt2x00dev->hw->workqueue, &rt2x00dev->filter_work);
}
EXPORT_SYMBOL_GPL(rt2x00mac_configure_filter);

#ifdef CONFIG_RT2X00_LIB_CRYPTO
static void memcpy_tkip(struct rt2x00lib_crypto *crypto, u8 *key, u8 key_len)
{
        if (key_len > NL80211_TKIP_DATA_OFFSET_ENCR_KEY)
                memcpy(&crypto->key,
                       &key[NL80211_TKIP_DATA_OFFSET_ENCR_KEY],
                       sizeof(crypto->key));

        if (key_len > NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY)
                memcpy(&crypto->tx_mic,
                       &key[NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY],
                       sizeof(crypto->tx_mic));

        if (key_len > NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY)
                memcpy(&crypto->rx_mic,
                       &key[NL80211_TKIP_DATA_OFFSET_RX_MIC_KEY],
                       sizeof(crypto->rx_mic));
}

int rt2x00mac_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 rt2x00_dev *rt2x00dev = hw->priv;
        struct rt2x00_intf *intf = vif_to_intf(vif);
        int (*set_key) (struct rt2x00_dev *rt2x00dev,
                        struct rt2x00lib_crypto *crypto,
                        struct ieee80211_key_conf *key);
        struct rt2x00lib_crypto crypto;
        static const u8 bcast_addr[ETH_ALEN] =
                { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, };

        if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
                return 0;
        else if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags))
                return -EOPNOTSUPP;
        else if (key->keylen > 32)
                return -ENOSPC;

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

        /*
         * When in STA mode, bssidx is always 0 otherwise local_address[5]
         * contains the bss number, see BSS_ID_MASK comments for details.
         */
        if (rt2x00dev->intf_sta_count)
                crypto.bssidx = 0;
        else
                crypto.bssidx = intf->mac[5] & (rt2x00dev->ops->max_ap_intf - 1);

        crypto.cipher = rt2x00crypto_key_to_cipher(key);
        if (crypto.cipher == CIPHER_NONE)
                return -EOPNOTSUPP;

        crypto.cmd = cmd;

        if (sta) {
                /* some drivers need the AID */
                crypto.aid = sta->aid;
                crypto.address = sta->addr;
        } else
                crypto.address = bcast_addr;

        if (crypto.cipher == CIPHER_TKIP)
                memcpy_tkip(&crypto, &key->key[0], key->keylen);
        else
                memcpy(&crypto.key, &key->key[0], key->keylen);
        /*
         * Each BSS has a maximum of 4 shared keys.
         * Shared key index values:
         *      0) BSS0 key0
         *      1) BSS0 key1
         *      ...
         *      4) BSS1 key0
         *      ...
         *      8) BSS2 key0
         *      ...
         * Both pairwise as shared key indeces are determined by
         * driver. This is required because the hardware requires
         * keys to be assigned in correct order (When key 1 is
         * provided but key 0 is not, then the key is not found
         * by the hardware during RX).
         */
        if (cmd == SET_KEY)
                key->hw_key_idx = 0;

        if (key->flags & IEEE80211_KEY_FLAG_PAIRWISE)
                set_key = rt2x00dev->ops->lib->config_pairwise_key;
        else
                set_key = rt2x00dev->ops->lib->config_shared_key;

        if (!set_key)
                return -EOPNOTSUPP;

        return set_key(rt2x00dev, &crypto, key);
}
EXPORT_SYMBOL_GPL(rt2x00mac_set_key);
#endif /* CONFIG_RT2X00_LIB_CRYPTO */

int rt2x00mac_get_stats(struct ieee80211_hw *hw,
                        struct ieee80211_low_level_stats *stats)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;

        /*
         * The dot11ACKFailureCount, dot11RTSFailureCount and
         * dot11RTSSuccessCount are updated in interrupt time.
         * dot11FCSErrorCount is updated in the link tuner.
         */
        memcpy(stats, &rt2x00dev->low_level_stats, sizeof(*stats));

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_get_stats);

int rt2x00mac_get_tx_stats(struct ieee80211_hw *hw,
                           struct ieee80211_tx_queue_stats *stats)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        unsigned int i;

        for (i = 0; i < rt2x00dev->ops->tx_queues; i++) {
                stats[i].len = rt2x00dev->tx[i].length;
                stats[i].limit = rt2x00dev->tx[i].limit;
                stats[i].count = rt2x00dev->tx[i].count;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_get_tx_stats);

void rt2x00mac_bss_info_changed(struct ieee80211_hw *hw,
                                struct ieee80211_vif *vif,
                                struct ieee80211_bss_conf *bss_conf,
                                u32 changes)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct rt2x00_intf *intf = vif_to_intf(vif);
        unsigned int delayed = 0;

        /*
         * When the association status has changed we must reset the link
         * tuner counter. This is because some drivers determine if they
         * should perform link tuning based on the number of seconds
         * while associated or not associated.
         */
        if (changes & BSS_CHANGED_ASSOC) {
                rt2x00dev->link.count = 0;

                if (bss_conf->assoc)
                        rt2x00dev->intf_associated++;
                else
                        rt2x00dev->intf_associated--;

                if (!test_bit(DRIVER_REQUIRE_SCHEDULED, &rt2x00dev->flags))
                        rt2x00leds_led_assoc(rt2x00dev,
                                             !!rt2x00dev->intf_associated);
                else
                        delayed |= DELAYED_LED_ASSOC;
        }

        /*
         * When the erp information has changed, we should perform
         * additional configuration steps. For all other changes we are done.
         */
        if (changes & ~(BSS_CHANGED_ASSOC | BSS_CHANGED_HT)) {
                if (!test_bit(DRIVER_REQUIRE_SCHEDULED, &rt2x00dev->flags))
                        rt2x00lib_config_erp(rt2x00dev, intf, bss_conf);
                else
                        delayed |= DELAYED_CONFIG_ERP;
        }

        spin_lock(&intf->lock);
        if (delayed) {
                intf->delayed_flags |= delayed;
                schedule_work(&rt2x00dev->intf_work);
        }
        spin_unlock(&intf->lock);
}
EXPORT_SYMBOL_GPL(rt2x00mac_bss_info_changed);

int rt2x00mac_conf_tx(struct ieee80211_hw *hw, u16 queue_idx,
                      const struct ieee80211_tx_queue_params *params)
{
        struct rt2x00_dev *rt2x00dev = hw->priv;
        struct data_queue *queue;

        queue = rt2x00queue_get_queue(rt2x00dev, queue_idx);
        if (unlikely(!queue))
                return -EINVAL;

        /*
         * The passed variables are stored as real value ((2^n)-1).
         * Ralink registers require to know the bit number 'n'.
         */
        if (params->cw_min > 0)
                queue->cw_min = fls(params->cw_min);
        else
                queue->cw_min = 5; /* cw_min: 2^5 = 32. */

        if (params->cw_max > 0)
                queue->cw_max = fls(params->cw_max);
        else
                queue->cw_max = 10; /* cw_min: 2^10 = 1024. */

        queue->aifs = params->aifs;
        queue->txop = params->txop;

        INFO(rt2x00dev,
             "Configured TX queue %d - CWmin: %d, CWmax: %d, Aifs: %d, TXop: %d.\n",
             queue_idx, queue->cw_min, queue->cw_max, queue->aifs, queue->txop);

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00mac_conf_tx);