rt2x00: Fix race condition when using inderect registers

[linux-2.6/btrfs-unstable.git] / drivers / net / wireless / rt2x00 / rt2x00dev.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: rt2x00lib
        Abstract: rt2x00 generic device routines.
 */

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

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

/*
 * Link tuning handlers
 */
void rt2x00lib_reset_link_tuner(struct rt2x00_dev *rt2x00dev)
{
        if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        /*
         * Reset link information.
         * Both the currently active vgc level as well as
         * the link tuner counter should be reset. Resetting
         * the counter is important for devices where the
         * device should only perform link tuning during the
         * first minute after being enabled.
         */
        rt2x00dev->link.count = 0;
        rt2x00dev->link.vgc_level = 0;

        /*
         * Reset the link tuner.
         */
        rt2x00dev->ops->lib->reset_tuner(rt2x00dev);
}

static void rt2x00lib_start_link_tuner(struct rt2x00_dev *rt2x00dev)
{
        /*
         * Clear all (possibly) pre-existing quality statistics.
         */
        memset(&rt2x00dev->link.qual, 0, sizeof(rt2x00dev->link.qual));

        /*
         * The RX and TX percentage should start at 50%
         * this will assure we will get at least get some
         * decent value when the link tuner starts.
         * The value will be dropped and overwritten with
         * the correct (measured )value anyway during the
         * first run of the link tuner.
         */
        rt2x00dev->link.qual.rx_percentage = 50;
        rt2x00dev->link.qual.tx_percentage = 50;

        rt2x00lib_reset_link_tuner(rt2x00dev);

        queue_delayed_work(rt2x00dev->hw->workqueue,
                           &rt2x00dev->link.work, LINK_TUNE_INTERVAL);
}

static void rt2x00lib_stop_link_tuner(struct rt2x00_dev *rt2x00dev)
{
        cancel_delayed_work_sync(&rt2x00dev->link.work);
}

/*
 * Radio control handlers.
 */
int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
{
        int status;

        /*
         * Don't enable the radio twice.
         * And check if the hardware button has been disabled.
         */
        if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
            test_bit(DEVICE_STATE_DISABLED_RADIO_HW, &rt2x00dev->flags))
                return 0;

        /*
         * Initialize all data queues.
         */
        rt2x00queue_init_queues(rt2x00dev);

        /*
         * Enable radio.
         */
        status =
            rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_ON);
        if (status)
                return status;

        rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_IRQ_ON);

        rt2x00leds_led_radio(rt2x00dev, true);
        rt2x00led_led_activity(rt2x00dev, true);

        set_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags);

        /*
         * Enable RX.
         */
        rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON);

        /*
         * Start the TX queues.
         */
        ieee80211_wake_queues(rt2x00dev->hw);

        return 0;
}

void rt2x00lib_disable_radio(struct rt2x00_dev *rt2x00dev)
{
        if (!test_and_clear_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        /*
         * Stop the TX queues.
         */
        ieee80211_stop_queues(rt2x00dev->hw);

        /*
         * Disable RX.
         */
        rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF);

        /*
         * Disable radio.
         */
        rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_OFF);
        rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_IRQ_OFF);
        rt2x00led_led_activity(rt2x00dev, false);
        rt2x00leds_led_radio(rt2x00dev, false);
}

void rt2x00lib_toggle_rx(struct rt2x00_dev *rt2x00dev, enum dev_state state)
{
        /*
         * When we are disabling the RX, we should also stop the link tuner.
         */
        if (state == STATE_RADIO_RX_OFF)
                rt2x00lib_stop_link_tuner(rt2x00dev);

        rt2x00dev->ops->lib->set_device_state(rt2x00dev, state);

        /*
         * When we are enabling the RX, we should also start the link tuner.
         */
        if (state == STATE_RADIO_RX_ON &&
            (rt2x00dev->intf_ap_count || rt2x00dev->intf_sta_count))
                rt2x00lib_start_link_tuner(rt2x00dev);
}

static void rt2x00lib_evaluate_antenna_sample(struct rt2x00_dev *rt2x00dev)
{
        struct antenna_setup ant;
        int sample_a =
            rt2x00_get_link_ant_rssi_history(&rt2x00dev->link, ANTENNA_A);
        int sample_b =
            rt2x00_get_link_ant_rssi_history(&rt2x00dev->link, ANTENNA_B);

        memcpy(&ant, &rt2x00dev->link.ant.active, sizeof(ant));

        /*
         * We are done sampling. Now we should evaluate the results.
         */
        rt2x00dev->link.ant.flags &= ~ANTENNA_MODE_SAMPLE;

        /*
         * During the last period we have sampled the RSSI
         * from both antenna's. It now is time to determine
         * which antenna demonstrated the best performance.
         * When we are already on the antenna with the best
         * performance, then there really is nothing for us
         * left to do.
         */
        if (sample_a == sample_b)
                return;

        if (rt2x00dev->link.ant.flags & ANTENNA_RX_DIVERSITY)
                ant.rx = (sample_a > sample_b) ? ANTENNA_A : ANTENNA_B;

        if (rt2x00dev->link.ant.flags & ANTENNA_TX_DIVERSITY)
                ant.tx = (sample_a > sample_b) ? ANTENNA_A : ANTENNA_B;

        rt2x00lib_config_antenna(rt2x00dev, &ant);
}

static void rt2x00lib_evaluate_antenna_eval(struct rt2x00_dev *rt2x00dev)
{
        struct antenna_setup ant;
        int rssi_curr = rt2x00_get_link_ant_rssi(&rt2x00dev->link);
        int rssi_old = rt2x00_update_ant_rssi(&rt2x00dev->link, rssi_curr);

        memcpy(&ant, &rt2x00dev->link.ant.active, sizeof(ant));

        /*
         * Legacy driver indicates that we should swap antenna's
         * when the difference in RSSI is greater that 5. This
         * also should be done when the RSSI was actually better
         * then the previous sample.
         * When the difference exceeds the threshold we should
         * sample the rssi from the other antenna to make a valid
         * comparison between the 2 antennas.
         */
        if (abs(rssi_curr - rssi_old) < 5)
                return;

        rt2x00dev->link.ant.flags |= ANTENNA_MODE_SAMPLE;

        if (rt2x00dev->link.ant.flags & ANTENNA_RX_DIVERSITY)
                ant.rx = (ant.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;

        if (rt2x00dev->link.ant.flags & ANTENNA_TX_DIVERSITY)
                ant.tx = (ant.tx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;

        rt2x00lib_config_antenna(rt2x00dev, &ant);
}

static void rt2x00lib_evaluate_antenna(struct rt2x00_dev *rt2x00dev)
{
        /*
         * Determine if software diversity is enabled for
         * either the TX or RX antenna (or both).
         * Always perform this check since within the link
         * tuner interval the configuration might have changed.
         */
        rt2x00dev->link.ant.flags &= ~ANTENNA_RX_DIVERSITY;
        rt2x00dev->link.ant.flags &= ~ANTENNA_TX_DIVERSITY;

        if (rt2x00dev->default_ant.rx == ANTENNA_SW_DIVERSITY)
                rt2x00dev->link.ant.flags |= ANTENNA_RX_DIVERSITY;
        if (rt2x00dev->default_ant.tx == ANTENNA_SW_DIVERSITY)
                rt2x00dev->link.ant.flags |= ANTENNA_TX_DIVERSITY;

        if (!(rt2x00dev->link.ant.flags & ANTENNA_RX_DIVERSITY) &&
            !(rt2x00dev->link.ant.flags & ANTENNA_TX_DIVERSITY)) {
                rt2x00dev->link.ant.flags = 0;
                return;
        }

        /*
         * If we have only sampled the data over the last period
         * we should now harvest the data. Otherwise just evaluate
         * the data. The latter should only be performed once
         * every 2 seconds.
         */
        if (rt2x00dev->link.ant.flags & ANTENNA_MODE_SAMPLE)
                rt2x00lib_evaluate_antenna_sample(rt2x00dev);
        else if (rt2x00dev->link.count & 1)
                rt2x00lib_evaluate_antenna_eval(rt2x00dev);
}

static void rt2x00lib_update_link_stats(struct link *link, int rssi)
{
        int avg_rssi = rssi;

        /*
         * Update global RSSI
         */
        if (link->qual.avg_rssi)
                avg_rssi = MOVING_AVERAGE(link->qual.avg_rssi, rssi, 8);
        link->qual.avg_rssi = avg_rssi;

        /*
         * Update antenna RSSI
         */
        if (link->ant.rssi_ant)
                rssi = MOVING_AVERAGE(link->ant.rssi_ant, rssi, 8);
        link->ant.rssi_ant = rssi;
}

static void rt2x00lib_precalculate_link_signal(struct link_qual *qual)
{
        if (qual->rx_failed || qual->rx_success)
                qual->rx_percentage =
                    (qual->rx_success * 100) /
                    (qual->rx_failed + qual->rx_success);
        else
                qual->rx_percentage = 50;

        if (qual->tx_failed || qual->tx_success)
                qual->tx_percentage =
                    (qual->tx_success * 100) /
                    (qual->tx_failed + qual->tx_success);
        else
                qual->tx_percentage = 50;

        qual->rx_success = 0;
        qual->rx_failed = 0;
        qual->tx_success = 0;
        qual->tx_failed = 0;
}

static int rt2x00lib_calculate_link_signal(struct rt2x00_dev *rt2x00dev,
                                           int rssi)
{
        int rssi_percentage = 0;
        int signal;

        /*
         * We need a positive value for the RSSI.
         */
        if (rssi < 0)
                rssi += rt2x00dev->rssi_offset;

        /*
         * Calculate the different percentages,
         * which will be used for the signal.
         */
        if (rt2x00dev->rssi_offset)
                rssi_percentage = (rssi * 100) / rt2x00dev->rssi_offset;

        /*
         * Add the individual percentages and use the WEIGHT
         * defines to calculate the current link signal.
         */
        signal = ((WEIGHT_RSSI * rssi_percentage) +
                  (WEIGHT_TX * rt2x00dev->link.qual.tx_percentage) +
                  (WEIGHT_RX * rt2x00dev->link.qual.rx_percentage)) / 100;

        return (signal > 100) ? 100 : signal;
}

static void rt2x00lib_link_tuner(struct work_struct *work)
{
        struct rt2x00_dev *rt2x00dev =
            container_of(work, struct rt2x00_dev, link.work.work);

        /*
         * When the radio is shutting down we should
         * immediately cease all link tuning.
         */
        if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        /*
         * Update statistics.
         */
        rt2x00dev->ops->lib->link_stats(rt2x00dev, &rt2x00dev->link.qual);
        rt2x00dev->low_level_stats.dot11FCSErrorCount +=
            rt2x00dev->link.qual.rx_failed;

        /*
         * Only perform the link tuning when Link tuning
         * has been enabled (This could have been disabled from the EEPROM).
         */
        if (!test_bit(CONFIG_DISABLE_LINK_TUNING, &rt2x00dev->flags))
                rt2x00dev->ops->lib->link_tuner(rt2x00dev);

        /*
         * Precalculate a portion of the link signal which is
         * in based on the tx/rx success/failure counters.
         */
        rt2x00lib_precalculate_link_signal(&rt2x00dev->link.qual);

        /*
         * Send a signal to the led to update the led signal strength.
         */
        rt2x00leds_led_quality(rt2x00dev, rt2x00dev->link.qual.avg_rssi);

        /*
         * Evaluate antenna setup, make this the last step since this could
         * possibly reset some statistics.
         */
        rt2x00lib_evaluate_antenna(rt2x00dev);

        /*
         * Increase tuner counter, and reschedule the next link tuner run.
         */
        rt2x00dev->link.count++;
        queue_delayed_work(rt2x00dev->hw->workqueue,
                           &rt2x00dev->link.work, LINK_TUNE_INTERVAL);
}

static void rt2x00lib_packetfilter_scheduled(struct work_struct *work)
{
        struct rt2x00_dev *rt2x00dev =
            container_of(work, struct rt2x00_dev, filter_work);

        rt2x00dev->ops->lib->config_filter(rt2x00dev, rt2x00dev->packet_filter);
}

static void rt2x00lib_intf_scheduled_iter(void *data, u8 *mac,
                                          struct ieee80211_vif *vif)
{
        struct rt2x00_dev *rt2x00dev = data;
        struct rt2x00_intf *intf = vif_to_intf(vif);
        struct ieee80211_bss_conf conf;
        int delayed_flags;

        /*
         * Copy all data we need during this action under the protection
         * of a spinlock. Otherwise race conditions might occur which results
         * into an invalid configuration.
         */
        spin_lock(&intf->lock);

        memcpy(&conf, &vif->bss_conf, sizeof(conf));
        delayed_flags = intf->delayed_flags;
        intf->delayed_flags = 0;

        spin_unlock(&intf->lock);

        /*
         * It is possible the radio was disabled while the work had been
         * scheduled. If that happens we should return here immediately,
         * note that in the spinlock protected area above the delayed_flags
         * have been cleared correctly.
         */
        if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        if (delayed_flags & DELAYED_UPDATE_BEACON)
                rt2x00queue_update_beacon(rt2x00dev, vif);

        if (delayed_flags & DELAYED_CONFIG_ERP)
                rt2x00lib_config_erp(rt2x00dev, intf, &conf);

        if (delayed_flags & DELAYED_LED_ASSOC)
                rt2x00leds_led_assoc(rt2x00dev, !!rt2x00dev->intf_associated);
}

static void rt2x00lib_intf_scheduled(struct work_struct *work)
{
        struct rt2x00_dev *rt2x00dev =
            container_of(work, struct rt2x00_dev, intf_work);

        /*
         * Iterate over each interface and perform the
         * requested configurations.
         */
        ieee80211_iterate_active_interfaces(rt2x00dev->hw,
                                            rt2x00lib_intf_scheduled_iter,
                                            rt2x00dev);
}

/*
 * Interrupt context handlers.
 */
static void rt2x00lib_beacondone_iter(void *data, u8 *mac,
                                      struct ieee80211_vif *vif)
{
        struct rt2x00_dev *rt2x00dev = data;
        struct rt2x00_intf *intf = vif_to_intf(vif);

        if (vif->type != NL80211_IFTYPE_AP &&
            vif->type != NL80211_IFTYPE_ADHOC)
                return;

        /*
         * Clean up the beacon skb.
         */
        rt2x00queue_free_skb(rt2x00dev, intf->beacon->skb);
        intf->beacon->skb = NULL;

        spin_lock(&intf->lock);
        intf->delayed_flags |= DELAYED_UPDATE_BEACON;
        spin_unlock(&intf->lock);
}

void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
{
        if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
                return;

        ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
                                                   rt2x00lib_beacondone_iter,
                                                   rt2x00dev);

        schedule_work(&rt2x00dev->intf_work);
}
EXPORT_SYMBOL_GPL(rt2x00lib_beacondone);

void rt2x00lib_txdone(struct queue_entry *entry,
                      struct txdone_entry_desc *txdesc)
{
        struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
        struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
        struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
        enum data_queue_qid qid = skb_get_queue_mapping(entry->skb);
        u8 rate_idx, rate_flags;

        /*
         * Unmap the skb.
         */
        rt2x00queue_unmap_skb(rt2x00dev, entry->skb);

        /*
         * If the IV/EIV data was stripped from the frame before it was
         * passed to the hardware, we should now reinsert it again because
         * mac80211 will expect the the same data to be present it the
         * frame as it was passed to us.
         */
        if (test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags))
                rt2x00crypto_tx_insert_iv(entry->skb);

        /*
         * Send frame to debugfs immediately, after this call is completed
         * we are going to overwrite the skb->cb array.
         */
        rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_TXDONE, entry->skb);

        /*
         * Update TX statistics.
         */
        rt2x00dev->link.qual.tx_success +=
            test_bit(TXDONE_SUCCESS, &txdesc->flags);
        rt2x00dev->link.qual.tx_failed +=
            test_bit(TXDONE_FAILURE, &txdesc->flags);

        rate_idx = skbdesc->tx_rate_idx;
        rate_flags = skbdesc->tx_rate_flags;

        /*
         * Initialize TX status
         */
        memset(&tx_info->status, 0, sizeof(tx_info->status));
        tx_info->status.ack_signal = 0;
        tx_info->status.rates[0].idx = rate_idx;
        tx_info->status.rates[0].flags = rate_flags;
        tx_info->status.rates[0].count = txdesc->retry + 1;
        tx_info->status.rates[1].idx = -1; /* terminate */

        if (!(tx_info->flags & IEEE80211_TX_CTL_NO_ACK)) {
                if (test_bit(TXDONE_SUCCESS, &txdesc->flags))
                        tx_info->flags |= IEEE80211_TX_STAT_ACK;
                else if (test_bit(TXDONE_FAILURE, &txdesc->flags))
                        rt2x00dev->low_level_stats.dot11ACKFailureCount++;
        }

        if (rate_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
                if (test_bit(TXDONE_SUCCESS, &txdesc->flags))
                        rt2x00dev->low_level_stats.dot11RTSSuccessCount++;
                else if (test_bit(TXDONE_FAILURE, &txdesc->flags))
                        rt2x00dev->low_level_stats.dot11RTSFailureCount++;
        }

        /*
         * Only send the status report to mac80211 when TX status was
         * requested by it. If this was a extra frame coming through
         * a mac80211 library call (RTS/CTS) then we should not send the
         * status report back.
         */
        if (tx_info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS)
                ieee80211_tx_status_irqsafe(rt2x00dev->hw, entry->skb);
        else
                dev_kfree_skb_irq(entry->skb);

        /*
         * Make this entry available for reuse.
         */
        entry->skb = NULL;
        entry->flags = 0;

        rt2x00dev->ops->lib->clear_entry(entry);

        clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
        rt2x00queue_index_inc(entry->queue, Q_INDEX_DONE);

        /*
         * If the data queue was below the threshold before the txdone
         * handler we must make sure the packet queue in the mac80211 stack
         * is reenabled when the txdone handler has finished.
         */
        if (!rt2x00queue_threshold(entry->queue))
                ieee80211_wake_queue(rt2x00dev->hw, qid);
}
EXPORT_SYMBOL_GPL(rt2x00lib_txdone);

void rt2x00lib_rxdone(struct rt2x00_dev *rt2x00dev,
                      struct queue_entry *entry)
{
        struct rxdone_entry_desc rxdesc;
        struct sk_buff *skb;
        struct ieee80211_rx_status *rx_status = &rt2x00dev->rx_status;
        struct ieee80211_supported_band *sband;
        struct ieee80211_hdr *hdr;
        const struct rt2x00_rate *rate;
        unsigned int header_length;
        unsigned int align;
        unsigned int i;
        int idx = -1;

        /*
         * Allocate a new sk_buffer. If no new buffer available, drop the
         * received frame and reuse the existing buffer.
         */
        skb = rt2x00queue_alloc_rxskb(rt2x00dev, entry);
        if (!skb)
                return;

        /*
         * Unmap the skb.
         */
        rt2x00queue_unmap_skb(rt2x00dev, entry->skb);

        /*
         * Extract the RXD details.
         */
        memset(&rxdesc, 0, sizeof(rxdesc));
        rt2x00dev->ops->lib->fill_rxdone(entry, &rxdesc);

        /*
         * The data behind the ieee80211 header must be
         * aligned on a 4 byte boundary.
         */
        header_length = ieee80211_get_hdrlen_from_skb(entry->skb);
        align = ((unsigned long)(entry->skb->data + header_length)) & 3;

        /*
         * Hardware might have stripped the IV/EIV/ICV data,
         * in that case it is possible that the data was
         * provided seperately (through hardware descriptor)
         * in which case we should reinsert the data into the frame.
         */
        if ((rxdesc.flags & RX_FLAG_IV_STRIPPED)) {
                rt2x00crypto_rx_insert_iv(entry->skb, align,
                                          header_length, &rxdesc);
        } else if (align) {
                skb_push(entry->skb, align);
                /* Move entire frame in 1 command */
                memmove(entry->skb->data, entry->skb->data + align,
                        rxdesc.size);
        }

        /* Update data pointers, trim buffer to correct size */
        skb_trim(entry->skb, rxdesc.size);

        /*
         * Update RX statistics.
         */
        sband = &rt2x00dev->bands[rt2x00dev->curr_band];
        for (i = 0; i < sband->n_bitrates; i++) {
                rate = rt2x00_get_rate(sband->bitrates[i].hw_value);

                if (((rxdesc.dev_flags & RXDONE_SIGNAL_PLCP) &&
                     (rate->plcp == rxdesc.signal)) ||
                    ((rxdesc.dev_flags & RXDONE_SIGNAL_BITRATE) &&
                      (rate->bitrate == rxdesc.signal))) {
                        idx = i;
                        break;
                }
        }

        if (idx < 0) {
                WARNING(rt2x00dev, "Frame received with unrecognized signal,"
                        "signal=0x%.2x, plcp=%d.\n", rxdesc.signal,
                        !!(rxdesc.dev_flags & RXDONE_SIGNAL_PLCP));
                idx = 0;
        }

        /*
         * Only update link status if this is a beacon frame carrying our bssid.
         */
        hdr = (struct ieee80211_hdr *)entry->skb->data;
        if (ieee80211_is_beacon(hdr->frame_control) &&
            (rxdesc.dev_flags & RXDONE_MY_BSS))
                rt2x00lib_update_link_stats(&rt2x00dev->link, rxdesc.rssi);

        rt2x00debug_update_crypto(rt2x00dev,
                                  rxdesc.cipher,
                                  rxdesc.cipher_status);

        rt2x00dev->link.qual.rx_success++;

        rx_status->mactime = rxdesc.timestamp;
        rx_status->rate_idx = idx;
        rx_status->qual =
            rt2x00lib_calculate_link_signal(rt2x00dev, rxdesc.rssi);
        rx_status->signal = rxdesc.rssi;
        rx_status->flag = rxdesc.flags;
        rx_status->antenna = rt2x00dev->link.ant.active.rx;

        /*
         * Send frame to mac80211 & debugfs.
         * mac80211 will clean up the skb structure.
         */
        rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_RXDONE, entry->skb);
        ieee80211_rx_irqsafe(rt2x00dev->hw, entry->skb, rx_status);

        /*
         * Replace the skb with the freshly allocated one.
         */
        entry->skb = skb;
        entry->flags = 0;

        rt2x00dev->ops->lib->clear_entry(entry);

        rt2x00queue_index_inc(entry->queue, Q_INDEX);
}
EXPORT_SYMBOL_GPL(rt2x00lib_rxdone);

/*
 * Driver initialization handlers.
 */
const struct rt2x00_rate rt2x00_supported_rates[12] = {
        {
                .flags = DEV_RATE_CCK,
                .bitrate = 10,
                .ratemask = BIT(0),
                .plcp = 0x00,
        },
        {
                .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
                .bitrate = 20,
                .ratemask = BIT(1),
                .plcp = 0x01,
        },
        {
                .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
                .bitrate = 55,
                .ratemask = BIT(2),
                .plcp = 0x02,
        },
        {
                .flags = DEV_RATE_CCK | DEV_RATE_SHORT_PREAMBLE,
                .bitrate = 110,
                .ratemask = BIT(3),
                .plcp = 0x03,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 60,
                .ratemask = BIT(4),
                .plcp = 0x0b,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 90,
                .ratemask = BIT(5),
                .plcp = 0x0f,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 120,
                .ratemask = BIT(6),
                .plcp = 0x0a,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 180,
                .ratemask = BIT(7),
                .plcp = 0x0e,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 240,
                .ratemask = BIT(8),
                .plcp = 0x09,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 360,
                .ratemask = BIT(9),
                .plcp = 0x0d,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 480,
                .ratemask = BIT(10),
                .plcp = 0x08,
        },
        {
                .flags = DEV_RATE_OFDM,
                .bitrate = 540,
                .ratemask = BIT(11),
                .plcp = 0x0c,
        },
};

static void rt2x00lib_channel(struct ieee80211_channel *entry,
                              const int channel, const int tx_power,
                              const int value)
{
        entry->center_freq = ieee80211_channel_to_frequency(channel);
        entry->hw_value = value;
        entry->max_power = tx_power;
        entry->max_antenna_gain = 0xff;
}

static void rt2x00lib_rate(struct ieee80211_rate *entry,
                           const u16 index, const struct rt2x00_rate *rate)
{
        entry->flags = 0;
        entry->bitrate = rate->bitrate;
        entry->hw_value = rt2x00_create_rate_hw_value(index, 0);
        entry->hw_value_short = entry->hw_value;

        if (rate->flags & DEV_RATE_SHORT_PREAMBLE) {
                entry->flags |= IEEE80211_RATE_SHORT_PREAMBLE;
                entry->hw_value_short |= rt2x00_create_rate_hw_value(index, 1);
        }
}

static int rt2x00lib_probe_hw_modes(struct rt2x00_dev *rt2x00dev,
                                    struct hw_mode_spec *spec)
{
        struct ieee80211_hw *hw = rt2x00dev->hw;
        struct ieee80211_channel *channels;
        struct ieee80211_rate *rates;
        unsigned int num_rates;
        unsigned int i;

        num_rates = 0;
        if (spec->supported_rates & SUPPORT_RATE_CCK)
                num_rates += 4;
        if (spec->supported_rates & SUPPORT_RATE_OFDM)
                num_rates += 8;

        channels = kzalloc(sizeof(*channels) * spec->num_channels, GFP_KERNEL);
        if (!channels)
                return -ENOMEM;

        rates = kzalloc(sizeof(*rates) * num_rates, GFP_KERNEL);
        if (!rates)
                goto exit_free_channels;

        /*
         * Initialize Rate list.
         */
        for (i = 0; i < num_rates; i++)
                rt2x00lib_rate(&rates[i], i, rt2x00_get_rate(i));

        /*
         * Initialize Channel list.
         */
        for (i = 0; i < spec->num_channels; i++) {
                rt2x00lib_channel(&channels[i],
                                  spec->channels[i].channel,
                                  spec->channels_info[i].tx_power1, i);
        }

        /*
         * Intitialize 802.11b, 802.11g
         * Rates: CCK, OFDM.
         * Channels: 2.4 GHz
         */
        if (spec->supported_bands & SUPPORT_BAND_2GHZ) {
                rt2x00dev->bands[IEEE80211_BAND_2GHZ].n_channels = 14;
                rt2x00dev->bands[IEEE80211_BAND_2GHZ].n_bitrates = num_rates;
                rt2x00dev->bands[IEEE80211_BAND_2GHZ].channels = channels;
                rt2x00dev->bands[IEEE80211_BAND_2GHZ].bitrates = rates;
                hw->wiphy->bands[IEEE80211_BAND_2GHZ] =
                    &rt2x00dev->bands[IEEE80211_BAND_2GHZ];
        }

        /*
         * Intitialize 802.11a
         * Rates: OFDM.
         * Channels: OFDM, UNII, HiperLAN2.
         */
        if (spec->supported_bands & SUPPORT_BAND_5GHZ) {
                rt2x00dev->bands[IEEE80211_BAND_5GHZ].n_channels =
                    spec->num_channels - 14;
                rt2x00dev->bands[IEEE80211_BAND_5GHZ].n_bitrates =
                    num_rates - 4;
                rt2x00dev->bands[IEEE80211_BAND_5GHZ].channels = &channels[14];
                rt2x00dev->bands[IEEE80211_BAND_5GHZ].bitrates = &rates[4];
                hw->wiphy->bands[IEEE80211_BAND_5GHZ] =
                    &rt2x00dev->bands[IEEE80211_BAND_5GHZ];
        }

        return 0;

 exit_free_channels:
        kfree(channels);
        ERROR(rt2x00dev, "Allocation ieee80211 modes failed.\n");
        return -ENOMEM;
}

static void rt2x00lib_remove_hw(struct rt2x00_dev *rt2x00dev)
{
        if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
                ieee80211_unregister_hw(rt2x00dev->hw);

        if (likely(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ])) {
                kfree(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ]->channels);
                kfree(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ]->bitrates);
                rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ] = NULL;
                rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_5GHZ] = NULL;
        }

        kfree(rt2x00dev->spec.channels_info);
}

static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
{
        struct hw_mode_spec *spec = &rt2x00dev->spec;
        int status;

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

        /*
         * Initialize HW modes.
         */
        status = rt2x00lib_probe_hw_modes(rt2x00dev, spec);
        if (status)
                return status;

        /*
         * Initialize HW fields.
         */
        rt2x00dev->hw->queues = rt2x00dev->ops->tx_queues;

        /*
         * Register HW.
         */
        status = ieee80211_register_hw(rt2x00dev->hw);
        if (status) {
                rt2x00lib_remove_hw(rt2x00dev);
                return status;
        }

        set_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags);

        return 0;
}

/*
 * Initialization/uninitialization handlers.
 */
static void rt2x00lib_uninitialize(struct rt2x00_dev *rt2x00dev)
{
        if (!test_and_clear_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
                return;

        /*
         * Unregister extra components.
         */
        rt2x00rfkill_unregister(rt2x00dev);

        /*
         * Allow the HW to uninitialize.
         */
        rt2x00dev->ops->lib->uninitialize(rt2x00dev);

        /*
         * Free allocated queue entries.
         */
        rt2x00queue_uninitialize(rt2x00dev);
}

static int rt2x00lib_initialize(struct rt2x00_dev *rt2x00dev)
{
        int status;

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

        /*
         * Allocate all queue entries.
         */
        status = rt2x00queue_initialize(rt2x00dev);
        if (status)
                return status;

        /*
         * Initialize the device.
         */
        status = rt2x00dev->ops->lib->initialize(rt2x00dev);
        if (status) {
                rt2x00queue_uninitialize(rt2x00dev);
                return status;
        }

        set_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags);

        /*
         * Register the extra components.
         */
        rt2x00rfkill_register(rt2x00dev);

        return 0;
}

int rt2x00lib_start(struct rt2x00_dev *rt2x00dev)
{
        int retval;

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

        /*
         * If this is the first interface which is added,
         * we should load the firmware now.
         */
        retval = rt2x00lib_load_firmware(rt2x00dev);
        if (retval)
                return retval;

        /*
         * Initialize the device.
         */
        retval = rt2x00lib_initialize(rt2x00dev);
        if (retval)
                return retval;

        rt2x00dev->intf_ap_count = 0;
        rt2x00dev->intf_sta_count = 0;
        rt2x00dev->intf_associated = 0;

        set_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags);

        return 0;
}

void rt2x00lib_stop(struct rt2x00_dev *rt2x00dev)
{
        if (!test_and_clear_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
                return;

        /*
         * Perhaps we can add something smarter here,
         * but for now just disabling the radio should do.
         */
        rt2x00lib_disable_radio(rt2x00dev);

        rt2x00dev->intf_ap_count = 0;
        rt2x00dev->intf_sta_count = 0;
        rt2x00dev->intf_associated = 0;
}

/*
 * driver allocation handlers.
 */
int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
{
        int retval = -ENOMEM;

        mutex_init(&rt2x00dev->csr_mutex);

        /*
         * Make room for rt2x00_intf inside the per-interface
         * structure ieee80211_vif.
         */
        rt2x00dev->hw->vif_data_size = sizeof(struct rt2x00_intf);

        /*
         * Determine which operating modes are supported, all modes
         * which require beaconing, depend on the availability of
         * beacon entries.
         */
        rt2x00dev->hw->wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION);
        if (rt2x00dev->ops->bcn->entry_num > 0)
                rt2x00dev->hw->wiphy->interface_modes |=
                    BIT(NL80211_IFTYPE_ADHOC) |
                    BIT(NL80211_IFTYPE_AP);

        /*
         * Let the driver probe the device to detect the capabilities.
         */
        retval = rt2x00dev->ops->lib->probe_hw(rt2x00dev);
        if (retval) {
                ERROR(rt2x00dev, "Failed to allocate device.\n");
                goto exit;
        }

        /*
         * Initialize configuration work.
         */
        INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
        INIT_WORK(&rt2x00dev->filter_work, rt2x00lib_packetfilter_scheduled);
        INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00lib_link_tuner);

        /*
         * Allocate queue array.
         */
        retval = rt2x00queue_allocate(rt2x00dev);
        if (retval)
                goto exit;

        /*
         * Initialize ieee80211 structure.
         */
        retval = rt2x00lib_probe_hw(rt2x00dev);
        if (retval) {
                ERROR(rt2x00dev, "Failed to initialize hw.\n");
                goto exit;
        }

        /*
         * Register extra components.
         */
        rt2x00leds_register(rt2x00dev);
        rt2x00rfkill_allocate(rt2x00dev);
        rt2x00debug_register(rt2x00dev);

        set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

        return 0;

exit:
        rt2x00lib_remove_dev(rt2x00dev);

        return retval;
}
EXPORT_SYMBOL_GPL(rt2x00lib_probe_dev);

void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
{
        clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

        /*
         * Disable radio.
         */
        rt2x00lib_disable_radio(rt2x00dev);

        /*
         * Uninitialize device.
         */
        rt2x00lib_uninitialize(rt2x00dev);

        /*
         * Free extra components
         */
        rt2x00debug_deregister(rt2x00dev);
        rt2x00rfkill_free(rt2x00dev);
        rt2x00leds_unregister(rt2x00dev);

        /*
         * Free ieee80211_hw memory.
         */
        rt2x00lib_remove_hw(rt2x00dev);

        /*
         * Free firmware image.
         */
        rt2x00lib_free_firmware(rt2x00dev);

        /*
         * Free queue structures.
         */
        rt2x00queue_free(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00lib_remove_dev);

/*
 * Device state handlers
 */
#ifdef CONFIG_PM
int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev, pm_message_t state)
{
        int retval;

        NOTICE(rt2x00dev, "Going to sleep.\n");

        /*
         * Only continue if mac80211 has open interfaces.
         */
        if (!test_and_clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
            !test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
                goto exit;

        set_bit(DEVICE_STATE_STARTED_SUSPEND, &rt2x00dev->flags);

        /*
         * Disable radio.
         */
        rt2x00lib_stop(rt2x00dev);
        rt2x00lib_uninitialize(rt2x00dev);

        /*
         * Suspend/disable extra components.
         */
        rt2x00leds_suspend(rt2x00dev);
        rt2x00debug_deregister(rt2x00dev);

exit:
        /*
         * Set device mode to sleep for power management,
         * on some hardware this call seems to consistently fail.
         * From the specifications it is hard to tell why it fails,
         * and if this is a "bad thing".
         * Overall it is safe to just ignore the failure and
         * continue suspending. The only downside is that the
         * device will not be in optimal power save mode, but with
         * the radio and the other components already disabled the
         * device is as good as disabled.
         */
        retval = rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_SLEEP);
        if (retval)
                WARNING(rt2x00dev, "Device failed to enter sleep state, "
                        "continue suspending.\n");

        return 0;
}
EXPORT_SYMBOL_GPL(rt2x00lib_suspend);

static void rt2x00lib_resume_intf(void *data, u8 *mac,
                                  struct ieee80211_vif *vif)
{
        struct rt2x00_dev *rt2x00dev = data;
        struct rt2x00_intf *intf = vif_to_intf(vif);

        spin_lock(&intf->lock);

        rt2x00lib_config_intf(rt2x00dev, intf,
                              vif->type, intf->mac, intf->bssid);


        /*
         * Master or Ad-hoc mode require a new beacon update.
         */
        if (vif->type == NL80211_IFTYPE_AP ||
            vif->type == NL80211_IFTYPE_ADHOC)
                intf->delayed_flags |= DELAYED_UPDATE_BEACON;

        spin_unlock(&intf->lock);
}

int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev)
{
        int retval;

        NOTICE(rt2x00dev, "Waking up.\n");

        /*
         * Restore/enable extra components.
         */
        rt2x00debug_register(rt2x00dev);
        rt2x00leds_resume(rt2x00dev);

        /*
         * Only continue if mac80211 had open interfaces.
         */
        if (!test_and_clear_bit(DEVICE_STATE_STARTED_SUSPEND, &rt2x00dev->flags))
                return 0;

        /*
         * Reinitialize device and all active interfaces.
         */
        retval = rt2x00lib_start(rt2x00dev);
        if (retval)
                goto exit;

        /*
         * Reconfigure device.
         */
        retval = rt2x00mac_config(rt2x00dev->hw, ~0);
        if (retval)
                goto exit;

        /*
         * Iterator over each active interface to
         * reconfigure the hardware.
         */
        ieee80211_iterate_active_interfaces(rt2x00dev->hw,
                                            rt2x00lib_resume_intf, rt2x00dev);

        /*
         * We are ready again to receive requests from mac80211.
         */
        set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);

        /*
         * It is possible that during that mac80211 has attempted
         * to send frames while we were suspending or resuming.
         * In that case we have disabled the TX queue and should
         * now enable it again
         */
        ieee80211_wake_queues(rt2x00dev->hw);

        /*
         * During interface iteration we might have changed the
         * delayed_flags, time to handles the event by calling
         * the work handler directly.
         */
        rt2x00lib_intf_scheduled(&rt2x00dev->intf_work);

        return 0;

exit:
        rt2x00lib_stop(rt2x00dev);
        rt2x00lib_uninitialize(rt2x00dev);
        rt2x00debug_deregister(rt2x00dev);

        return retval;
}
EXPORT_SYMBOL_GPL(rt2x00lib_resume);
#endif /* CONFIG_PM */

/*
 * rt2x00lib module information.
 */
MODULE_AUTHOR(DRV_PROJECT);
MODULE_VERSION(DRV_VERSION);
MODULE_DESCRIPTION("rt2x00 library");
MODULE_LICENSE("GPL");