ps.c

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/*
 * This file is part of wl1271
 *
 * Copyright (C) 2008-2009 Nokia Corporation
 *
 * Contact: Luciano Coelho <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include "ps.h"
#include "io.h"
#include "tx.h"
#include "debug.h"

#define WL1271_WAKEUP_TIMEOUT 500

#define ELP_ENTRY_DELAY  30

void wl1271_elp_work(struct work_struct *work)
{
    struct delayed_work *dwork;
    struct wl1271 *wl;
    struct wl12xx_vif *wlvif;
    int ret;

    dwork = container_of(work, struct delayed_work, work);
    wl = container_of(dwork, struct wl1271, elp_work);

    wl1271_debug(DEBUG_PSM, "elp work");

    mutex_lock(&wl->mutex);

    if (unlikely(wl->state != WLCORE_STATE_ON))
        goto out;

    /* our work might have been already cancelled */
    if (unlikely(!test_bit(WL1271_FLAG_ELP_REQUESTED, &wl->flags)))
        goto out;

    if (test_bit(WL1271_FLAG_IN_ELP, &wl->flags))
        goto out;

    wl12xx_for_each_wlvif(wl, wlvif) {
        if (wlvif->bss_type == BSS_TYPE_AP_BSS)
            goto out;

        if (!test_bit(WLVIF_FLAG_IN_PS, &wlvif->flags) &&
            test_bit(WLVIF_FLAG_IN_USE, &wlvif->flags))
            goto out;
    }

    wl1271_debug(DEBUG_PSM, "chip to elp");
    ret = wlcore_raw_write32(wl, HW_ACCESS_ELP_CTRL_REG, ELPCTRL_SLEEP);
    if (ret < 0) {
        wl12xx_queue_recovery_work(wl);
        goto out;
    }

    set_bit(WL1271_FLAG_IN_ELP, &wl->flags);

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

/* Routines to toggle sleep mode while in ELP */
void wl1271_ps_elp_sleep(struct wl1271 *wl)
{
    struct wl12xx_vif *wlvif;
    u32 timeout;

    if (wl->sleep_auth != WL1271_PSM_ELP)
        return;

    /* we shouldn't get consecutive sleep requests */
    if (WARN_ON(test_and_set_bit(WL1271_FLAG_ELP_REQUESTED, &wl->flags)))
        return;

    wl12xx_for_each_wlvif(wl, wlvif) {
        if (wlvif->bss_type == BSS_TYPE_AP_BSS)
            return;

        if (!test_bit(WLVIF_FLAG_IN_PS, &wlvif->flags) &&
            test_bit(WLVIF_FLAG_IN_USE, &wlvif->flags))
            return;
    }

    timeout = ELP_ENTRY_DELAY;
    ieee80211_queue_delayed_work(wl->hw, &wl->elp_work,
                     msecs_to_jiffies(timeout));
}

int wl1271_ps_elp_wakeup(struct wl1271 *wl)
{
    DECLARE_COMPLETION_ONSTACK(compl);
    unsigned long flags;
    int ret;
    u32 start_time = jiffies;
    bool pending = false;

    /*
     * we might try to wake up even if we didn't go to sleep
     * before (e.g. on boot)
     */
    if (!test_and_clear_bit(WL1271_FLAG_ELP_REQUESTED, &wl->flags))
        return 0;

    /* don't cancel_sync as it might contend for a mutex and deadlock */
    cancel_delayed_work(&wl->elp_work);

    if (!test_bit(WL1271_FLAG_IN_ELP, &wl->flags))
        return 0;

    wl1271_debug(DEBUG_PSM, "waking up chip from elp");

    /*
     * The spinlock is required here to synchronize both the work and
     * the completion variable in one entity.
     */
    spin_lock_irqsave(&wl->wl_lock, flags);
    if (test_bit(WL1271_FLAG_IRQ_RUNNING, &wl->flags))
        pending = true;
    else
        wl->elp_compl = &compl;
    spin_unlock_irqrestore(&wl->wl_lock, flags);

    ret = wlcore_raw_write32(wl, HW_ACCESS_ELP_CTRL_REG, ELPCTRL_WAKE_UP);
    if (ret < 0) {
        wl12xx_queue_recovery_work(wl);
        goto err;
    }

    if (!pending) {
        ret = wait_for_completion_timeout(
            &compl, msecs_to_jiffies(WL1271_WAKEUP_TIMEOUT));
        if (ret == 0) {
            wl1271_error("ELP wakeup timeout!");
            wl12xx_queue_recovery_work(wl);
            ret = -ETIMEDOUT;
            goto err;
        } else if (ret < 0) {
            wl1271_error("ELP wakeup completion error.");
            goto err;
        }
    }

    clear_bit(WL1271_FLAG_IN_ELP, &wl->flags);

    wl1271_debug(DEBUG_PSM, "wakeup time: %u ms",
             jiffies_to_msecs(jiffies - start_time));
    goto out;

err:
    spin_lock_irqsave(&wl->wl_lock, flags);
    wl->elp_compl = NULL;
    spin_unlock_irqrestore(&wl->wl_lock, flags);
    return ret;

out:
    return 0;
}

int wl1271_ps_set_mode(struct wl1271 *wl, struct wl12xx_vif *wlvif,
               enum wl1271_cmd_ps_mode mode)
{
    int ret;
    u16 timeout = wl->conf.conn.dynamic_ps_timeout;

    switch (mode) {
    case STATION_AUTO_PS_MODE:
    case STATION_POWER_SAVE_MODE:
        wl1271_debug(DEBUG_PSM, "entering psm (mode=%d,timeout=%u)",
                 mode, timeout);

        ret = wl1271_acx_wake_up_conditions(wl, wlvif,
                        wl->conf.conn.wake_up_event,
                        wl->conf.conn.listen_interval);
        if (ret < 0) {
            wl1271_error("couldn't set wake up conditions");
            return ret;
        }

        ret = wl1271_cmd_ps_mode(wl, wlvif, mode, timeout);
        if (ret < 0)
            return ret;

        set_bit(WLVIF_FLAG_IN_PS, &wlvif->flags);

        /*
         * enable beacon early termination.
         * Not relevant for 5GHz and for high rates.
         */
        if ((wlvif->band == IEEE80211_BAND_2GHZ) &&
            (wlvif->basic_rate < CONF_HW_BIT_RATE_9MBPS)) {
            ret = wl1271_acx_bet_enable(wl, wlvif, true);
            if (ret < 0)
                return ret;
        }
        break;
    case STATION_ACTIVE_MODE:
        wl1271_debug(DEBUG_PSM, "leaving psm");

        /* disable beacon early termination */
        if ((wlvif->band == IEEE80211_BAND_2GHZ) &&
            (wlvif->basic_rate < CONF_HW_BIT_RATE_9MBPS)) {
            ret = wl1271_acx_bet_enable(wl, wlvif, false);
            if (ret < 0)
                return ret;
        }

        ret = wl1271_cmd_ps_mode(wl, wlvif, mode, 0);
        if (ret < 0)
            return ret;

        clear_bit(WLVIF_FLAG_IN_PS, &wlvif->flags);
        break;
    default:
        wl1271_warning("trying to set ps to unsupported mode %d", mode);
        ret = -EINVAL;
    }

    return ret;
}

static void wl1271_ps_filter_frames(struct wl1271 *wl, u8 hlid)
{
    int i;
    struct sk_buff *skb;
    struct ieee80211_tx_info *info;
    unsigned long flags;
    int filtered[NUM_TX_QUEUES];

    /* filter all frames currently in the low level queues for this hlid */
    for (i = 0; i < NUM_TX_QUEUES; i++) {
        filtered[i] = 0;
        while ((skb = skb_dequeue(&wl->links[hlid].tx_queue[i]))) {
            filtered[i]++;

            if (WARN_ON(wl12xx_is_dummy_packet(wl, skb)))
                continue;

            info = IEEE80211_SKB_CB(skb);
            info->flags |= IEEE80211_TX_STAT_TX_FILTERED;
            info->status.rates[0].idx = -1;
            ieee80211_tx_status_ni(wl->hw, skb);
        }
    }

    spin_lock_irqsave(&wl->wl_lock, flags);
    for (i = 0; i < NUM_TX_QUEUES; i++)
        wl->tx_queue_count[i] -= filtered[i];
    spin_unlock_irqrestore(&wl->wl_lock, flags);

    wl1271_handle_tx_low_watermark(wl);
}

void wl12xx_ps_link_start(struct wl1271 *wl, struct wl12xx_vif *wlvif,
              u8 hlid, bool clean_queues)
{
    struct ieee80211_sta *sta;
    struct ieee80211_vif *vif = wl12xx_wlvif_to_vif(wlvif);

    if (test_bit(hlid, &wl->ap_ps_map))
        return;

    wl1271_debug(DEBUG_PSM, "start mac80211 PSM on hlid %d pkts %d "
             "clean_queues %d", hlid, wl->links[hlid].allocated_pkts,
             clean_queues);

    rcu_read_lock();
    sta = ieee80211_find_sta(vif, wl->links[hlid].addr);
    if (!sta) {
        wl1271_error("could not find sta %pM for starting ps",
                 wl->links[hlid].addr);
        rcu_read_unlock();
        return;
    }

    ieee80211_sta_ps_transition_ni(sta, true);
    rcu_read_unlock();

    /* do we want to filter all frames from this link's queues? */
    if (clean_queues)
        wl1271_ps_filter_frames(wl, hlid);

    __set_bit(hlid, &wl->ap_ps_map);
}

void wl12xx_ps_link_end(struct wl1271 *wl, struct wl12xx_vif *wlvif, u8 hlid)
{
    struct ieee80211_sta *sta;
    struct ieee80211_vif *vif = wl12xx_wlvif_to_vif(wlvif);

    if (!test_bit(hlid, &wl->ap_ps_map))
        return;

    wl1271_debug(DEBUG_PSM, "end mac80211 PSM on hlid %d", hlid);

    __clear_bit(hlid, &wl->ap_ps_map);

    rcu_read_lock();
    sta = ieee80211_find_sta(vif, wl->links[hlid].addr);
    if (!sta) {
        wl1271_error("could not find sta %pM for ending ps",
                 wl->links[hlid].addr);
        goto end;
    }

    ieee80211_sta_ps_transition_ni(sta, false);
end:
    rcu_read_unlock();
}