irlap_event.c

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/*********************************************************************
 *
 * Filename:      irlap_event.c
 * Version:       0.9
 * Description:   IrLAP state machine implementation
 * Status:        Experimental.
 * Author:        Dag Brattli <[email protected]>
 * Created at:    Sat Aug 16 00:59:29 1997
 * Modified at:   Sat Dec 25 21:07:57 1999
 * Modified by:   Dag Brattli <[email protected]>
 *
 *     Copyright (c) 1998-2000 Dag Brattli <[email protected]>,
 *     Copyright (c) 1998      Thomas Davis <[email protected]>
 *     All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <[email protected]>
 *
 *     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.
 *
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is
 *     provided "AS-IS" and at no charge.
 *
 ********************************************************************/

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/skbuff.h>
#include <linux/slab.h>

#include <net/irda/irda.h>
#include <net/irda/irlap_event.h>

#include <net/irda/timer.h>
#include <net/irda/irlap.h>
#include <net/irda/irlap_frame.h>
#include <net/irda/qos.h>
#include <net/irda/parameters.h>
#include <net/irda/irlmp.h>     /* irlmp_flow_indication(), ... */

#include <net/irda/irda_device.h>

#ifdef CONFIG_IRDA_FAST_RR
int sysctl_fast_poll_increase = 50;
#endif

static int irlap_state_ndm    (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_query  (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reply  (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_conn   (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_setup  (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_xmit_p (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_pclose (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_nrm_p  (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
                  struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset  (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_nrm_s  (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_xmit_s (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_sclose (struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info);
static int irlap_state_reset_check(struct irlap_cb *, IRLAP_EVENT event,
                   struct sk_buff *, struct irlap_info *);

#ifdef CONFIG_IRDA_DEBUG
static const char *const irlap_event[] = {
    "DISCOVERY_REQUEST",
    "CONNECT_REQUEST",
    "CONNECT_RESPONSE",
    "DISCONNECT_REQUEST",
    "DATA_REQUEST",
    "RESET_REQUEST",
    "RESET_RESPONSE",
    "SEND_I_CMD",
    "SEND_UI_FRAME",
    "RECV_DISCOVERY_XID_CMD",
    "RECV_DISCOVERY_XID_RSP",
    "RECV_SNRM_CMD",
    "RECV_TEST_CMD",
    "RECV_TEST_RSP",
    "RECV_UA_RSP",
    "RECV_DM_RSP",
    "RECV_RD_RSP",
    "RECV_I_CMD",
    "RECV_I_RSP",
    "RECV_UI_FRAME",
    "RECV_FRMR_RSP",
    "RECV_RR_CMD",
    "RECV_RR_RSP",
    "RECV_RNR_CMD",
    "RECV_RNR_RSP",
    "RECV_REJ_CMD",
    "RECV_REJ_RSP",
    "RECV_SREJ_CMD",
    "RECV_SREJ_RSP",
    "RECV_DISC_CMD",
    "SLOT_TIMER_EXPIRED",
    "QUERY_TIMER_EXPIRED",
    "FINAL_TIMER_EXPIRED",
    "POLL_TIMER_EXPIRED",
    "DISCOVERY_TIMER_EXPIRED",
    "WD_TIMER_EXPIRED",
    "BACKOFF_TIMER_EXPIRED",
    "MEDIA_BUSY_TIMER_EXPIRED",
};
#endif  /* CONFIG_IRDA_DEBUG */

const char *const irlap_state[] = {
    "LAP_NDM",
    "LAP_QUERY",
    "LAP_REPLY",
    "LAP_CONN",
    "LAP_SETUP",
    "LAP_OFFLINE",
    "LAP_XMIT_P",
    "LAP_PCLOSE",
    "LAP_NRM_P",
    "LAP_RESET_WAIT",
    "LAP_RESET",
    "LAP_NRM_S",
    "LAP_XMIT_S",
    "LAP_SCLOSE",
    "LAP_RESET_CHECK",
};

static int (*state[])(struct irlap_cb *self, IRLAP_EVENT event,
              struct sk_buff *skb, struct irlap_info *info) =
{
    irlap_state_ndm,
    irlap_state_query,
    irlap_state_reply,
    irlap_state_conn,
    irlap_state_setup,
    irlap_state_offline,
    irlap_state_xmit_p,
    irlap_state_pclose,
    irlap_state_nrm_p,
    irlap_state_reset_wait,
    irlap_state_reset,
    irlap_state_nrm_s,
    irlap_state_xmit_s,
    irlap_state_sclose,
    irlap_state_reset_check,
};

/*
 * Function irda_poll_timer_expired (data)
 *
 *    Poll timer has expired. Normally we must now send a RR frame to the
 *    remote device
 */
static void irlap_poll_timer_expired(void *data)
{
    struct irlap_cb *self = (struct irlap_cb *) data;

    IRDA_ASSERT(self != NULL, return;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

    irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
}

/*
 * Calculate and set time before we will have to send back the pf bit
 * to the peer. Use in primary.
 * Make sure that state is XMIT_P/XMIT_S when calling this function
 * (and that nobody messed up with the state). - Jean II
 */
static void irlap_start_poll_timer(struct irlap_cb *self, int timeout)
{
    IRDA_ASSERT(self != NULL, return;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

#ifdef CONFIG_IRDA_FAST_RR
    /*
     * Send out the RR frames faster if our own transmit queue is empty, or
     * if the peer is busy. The effect is a much faster conversation
     */
    if (skb_queue_empty(&self->txq) || self->remote_busy) {
        if (self->fast_RR == TRUE) {
            /*
             *  Assert that the fast poll timer has not reached the
             *  normal poll timer yet
             */
            if (self->fast_RR_timeout < timeout) {
                /*
                 *  FIXME: this should be a more configurable
                 *         function
                 */
                self->fast_RR_timeout +=
                    (sysctl_fast_poll_increase * HZ/1000);

                /* Use this fast(er) timeout instead */
                timeout = self->fast_RR_timeout;
            }
        } else {
            self->fast_RR = TRUE;

            /* Start with just 0 ms */
            self->fast_RR_timeout = 0;
            timeout = 0;
        }
    } else
        self->fast_RR = FALSE;

    IRDA_DEBUG(3, "%s(), timeout=%d (%ld)\n", __func__, timeout, jiffies);
#endif /* CONFIG_IRDA_FAST_RR */

    if (timeout == 0)
        irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
    else
        irda_start_timer(&self->poll_timer, timeout, self,
                 irlap_poll_timer_expired);
}

/*
 * Function irlap_do_event (event, skb, info)
 *
 *    Rushes through the state machine without any delay. If state == XMIT
 *    then send queued data frames.
 */
void irlap_do_event(struct irlap_cb *self, IRLAP_EVENT event,
            struct sk_buff *skb, struct irlap_info *info)
{
    int ret;

    if (!self || self->magic != LAP_MAGIC)
        return;

    IRDA_DEBUG(3, "%s(), event = %s, state = %s\n", __func__,
           irlap_event[event], irlap_state[self->state]);

    ret = (*state[self->state])(self, event, skb, info);

    /*
     *  Check if there are any pending events that needs to be executed
     */
    switch (self->state) {
    case LAP_XMIT_P: /* FALLTHROUGH */
    case LAP_XMIT_S:
        /*
         * We just received the pf bit and are at the beginning
         * of a new LAP transmit window.
         * Check if there are any queued data frames, and do not
         * try to disconnect link if we send any data frames, since
         * that will change the state away form XMIT
         */
        IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
               skb_queue_len(&self->txq));

        if (!skb_queue_empty(&self->txq)) {
            /* Prevent race conditions with irlap_data_request() */
            self->local_busy = TRUE;

            /* Theory of operation.
             * We send frames up to when we fill the window or
             * reach line capacity. Those frames will queue up
             * in the device queue, and the driver will slowly
             * send them.
             * After each frame that we send, we poll the higher
             * layer for more data. It's the right time to do
             * that because the link layer need to perform the mtt
             * and then send the first frame, so we can afford
             * to send a bit of time in kernel space.
             * The explicit flow indication allow to minimise
             * buffers (== lower latency), to avoid higher layer
             * polling via timers (== less context switches) and
             * to implement a crude scheduler - Jean II */

            /* Try to send away all queued data frames */
            while ((skb = skb_dequeue(&self->txq)) != NULL) {
                /* Send one frame */
                ret = (*state[self->state])(self, SEND_I_CMD,
                                skb, NULL);
                /* Drop reference count.
                 * It will be increase as needed in
                 * irlap_send_data_xxx() */
                kfree_skb(skb);

                /* Poll the higher layers for one more frame */
                irlmp_flow_indication(self->notify.instance,
                              FLOW_START);

                if (ret == -EPROTO)
                    break; /* Try again later! */
            }
            /* Finished transmitting */
            self->local_busy = FALSE;
        } else if (self->disconnect_pending) {
            self->disconnect_pending = FALSE;

            ret = (*state[self->state])(self, DISCONNECT_REQUEST,
                            NULL, NULL);
        }
        break;
/*  case LAP_NDM: */
/*  case LAP_CONN: */
/*  case LAP_RESET_WAIT: */
/*  case LAP_RESET_CHECK: */
    default:
        break;
    }
}

/*
 * Function irlap_state_ndm (event, skb, frame)
 *
 *    NDM (Normal Disconnected Mode) state
 *
 */
static int irlap_state_ndm(struct irlap_cb *self, IRLAP_EVENT event,
               struct sk_buff *skb, struct irlap_info *info)
{
    discovery_t *discovery_rsp;
    int ret = 0;

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case CONNECT_REQUEST:
        IRDA_ASSERT(self->netdev != NULL, return -1;);

        if (self->media_busy) {
            /* Note : this will never happen, because we test
             * media busy in irlap_connect_request() and
             * postpone the event... - Jean II */
            IRDA_DEBUG(0, "%s(), CONNECT_REQUEST: media busy!\n",
                   __func__);

            /* Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);

            irlap_disconnect_indication(self, LAP_MEDIA_BUSY);
        } else {
            irlap_send_snrm_frame(self, &self->qos_rx);

            /* Start Final-bit timer */
            irlap_start_final_timer(self, self->final_timeout);

            self->retry_count = 0;
            irlap_next_state(self, LAP_SETUP);
        }
        break;
    case RECV_SNRM_CMD:
        /* Check if the frame contains and I field */
        if (info) {
            self->daddr = info->daddr;
            self->caddr = info->caddr;

            irlap_next_state(self, LAP_CONN);

            irlap_connect_indication(self, skb);
        } else {
            IRDA_DEBUG(0, "%s(), SNRM frame does not "
                   "contain an I field!\n", __func__);
        }
        break;
    case DISCOVERY_REQUEST:
        IRDA_ASSERT(info != NULL, return -1;);

        if (self->media_busy) {
            IRDA_DEBUG(1, "%s(), DISCOVERY_REQUEST: media busy!\n",
                   __func__);
            /* irlap->log.condition = MEDIA_BUSY; */

            /* This will make IrLMP try again */
            irlap_discovery_confirm(self, NULL);
            /* Note : the discovery log is not cleaned up here,
             * it will be done in irlap_discovery_request()
             * Jean II */
            return 0;
        }

        self->S = info->S;
        self->s = info->s;
        irlap_send_discovery_xid_frame(self, info->S, info->s, TRUE,
                           info->discovery);
        self->frame_sent = FALSE;
        self->s++;

        irlap_start_slot_timer(self, self->slot_timeout);
        irlap_next_state(self, LAP_QUERY);
        break;
    case RECV_DISCOVERY_XID_CMD:
        IRDA_ASSERT(info != NULL, return -1;);

        /* Assert that this is not the final slot */
        if (info->s <= info->S) {
            self->slot = irlap_generate_rand_time_slot(info->S,
                                   info->s);
            if (self->slot == info->s) {
                discovery_rsp = irlmp_get_discovery_response();
                discovery_rsp->data.daddr = info->daddr;

                irlap_send_discovery_xid_frame(self, info->S,
                                   self->slot,
                                   FALSE,
                                   discovery_rsp);
                self->frame_sent = TRUE;
            } else
                self->frame_sent = FALSE;

            /*
             * Go to reply state until end of discovery to
             * inhibit our own transmissions. Set the timer
             * to not stay forever there... Jean II
             */
            irlap_start_query_timer(self, info->S, info->s);
            irlap_next_state(self, LAP_REPLY);
        } else {
        /* This is the final slot. How is it possible ?
         * This would happen is both discoveries are just slightly
         * offset (if they are in sync, all packets are lost).
         * Most often, all the discovery requests will be received
         * in QUERY state (see my comment there), except for the
         * last frame that will come here.
         * The big trouble when it happen is that active discovery
         * doesn't happen, because nobody answer the discoveries
         * frame of the other guy, so the log shows up empty.
         * What should we do ?
         * Not much. It's too late to answer those discovery frames,
         * so we just pass the info to IrLMP who will put it in the
         * log (and post an event).
         * Another cause would be devices that do discovery much
         * slower than us, however the latest fixes should minimise
         * those cases...
         * Jean II
         */
            IRDA_DEBUG(1, "%s(), Receiving final discovery request, missed the discovery slots :-(\n", __func__);

            /* Last discovery request -> in the log */
            irlap_discovery_indication(self, info->discovery);
        }
        break;
    case MEDIA_BUSY_TIMER_EXPIRED:
        /* A bunch of events may be postponed because the media is
         * busy (usually immediately after we close a connection),
         * or while we are doing discovery (state query/reply).
         * In all those cases, the media busy flag will be cleared
         * when it's OK for us to process those postponed events.
         * This event is not mentioned in the state machines in the
         * IrLAP spec. It's because they didn't consider Ultra and
         * postponing connection request is optional.
         * Jean II */
#ifdef CONFIG_IRDA_ULTRA
        /* Send any pending Ultra frames if any */
        if (!skb_queue_empty(&self->txq_ultra)) {
            /* We don't send the frame, just post an event.
             * Also, previously this code was in timer.c...
             * Jean II */
            ret = (*state[self->state])(self, SEND_UI_FRAME,
                            NULL, NULL);
        }
#endif /* CONFIG_IRDA_ULTRA */
        /* Check if we should try to connect.
         * This code was previously in irlap_do_event() */
        if (self->connect_pending) {
            self->connect_pending = FALSE;

            /* This one *should* not pend in this state, except
             * if a socket try to connect and immediately
             * disconnect. - clear - Jean II */
            if (self->disconnect_pending)
                irlap_disconnect_indication(self, LAP_DISC_INDICATION);
            else
                ret = (*state[self->state])(self,
                                CONNECT_REQUEST,
                                NULL, NULL);
            self->disconnect_pending = FALSE;
        }
        /* Note : one way to test if this code works well (including
         * media busy and small busy) is to create a user space
         * application generating an Ultra packet every 3.05 sec (or
         * 2.95 sec) and to see how it interact with discovery.
         * It's fairly easy to check that no packet is lost, that the
         * packets are postponed during discovery and that after
         * discovery indication you have a 100ms "gap".
         * As connection request and Ultra are now processed the same
         * way, this avoid the tedious job of trying IrLAP connection
         * in all those cases...
         * Jean II */
        break;
#ifdef CONFIG_IRDA_ULTRA
    case SEND_UI_FRAME:
    {
        int i;
        /* Only allowed to repeat an operation twice */
        for (i=0; ((i<2) && (self->media_busy == FALSE)); i++) {
            skb = skb_dequeue(&self->txq_ultra);
            if (skb)
                irlap_send_ui_frame(self, skb, CBROADCAST,
                            CMD_FRAME);
            else
                break;
            /* irlap_send_ui_frame() won't increase skb reference
             * count, so no dev_kfree_skb() - Jean II */
        }
        if (i == 2) {
            /* Force us to listen 500 ms again */
            irda_device_set_media_busy(self->netdev, TRUE);
        }
        break;
    }
    case RECV_UI_FRAME:
        /* Only accept broadcast frames in NDM mode */
        if (info->caddr != CBROADCAST) {
            IRDA_DEBUG(0, "%s(), not a broadcast frame!\n",
                   __func__);
        } else
            irlap_unitdata_indication(self, skb);
        break;
#endif /* CONFIG_IRDA_ULTRA */
    case RECV_TEST_CMD:
        /* Remove test frame header */
        skb_pull(skb, sizeof(struct test_frame));

        /*
         * Send response. This skb will not be sent out again, and
         * will only be used to send out the same info as the cmd
         */
        irlap_send_test_frame(self, CBROADCAST, info->daddr, skb);
        break;
    case RECV_TEST_RSP:
        IRDA_DEBUG(0, "%s() not implemented!\n", __func__);
        break;
    default:
        IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
               irlap_event[event]);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_query (event, skb, info)
 *
 *    QUERY state
 *
 */
static int irlap_state_query(struct irlap_cb *self, IRLAP_EVENT event,
                 struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case RECV_DISCOVERY_XID_RSP:
        IRDA_ASSERT(info != NULL, return -1;);
        IRDA_ASSERT(info->discovery != NULL, return -1;);

        IRDA_DEBUG(4, "%s(), daddr=%08x\n", __func__,
               info->discovery->data.daddr);

        if (!self->discovery_log) {
            IRDA_WARNING("%s: discovery log is gone! "
                     "maybe the discovery timeout has been set"
                     " too short?\n", __func__);
            break;
        }
        hashbin_insert(self->discovery_log,
                   (irda_queue_t *) info->discovery,
                   info->discovery->data.daddr, NULL);

        /* Keep state */
        /* irlap_next_state(self, LAP_QUERY);  */

        break;
    case RECV_DISCOVERY_XID_CMD:
        /* Yes, it is possible to receive those frames in this mode.
         * Note that most often the last discovery request won't
         * occur here but in NDM state (see my comment there).
         * What should we do ?
         * Not much. We are currently performing our own discovery,
         * therefore we can't answer those frames. We don't want
         * to change state either. We just pass the info to
         * IrLMP who will put it in the log (and post an event).
         * Jean II
         */

        IRDA_ASSERT(info != NULL, return -1;);

        IRDA_DEBUG(1, "%s(), Receiving discovery request (s = %d) while performing discovery :-(\n", __func__, info->s);

        /* Last discovery request ? */
        if (info->s == 0xff)
            irlap_discovery_indication(self, info->discovery);
        break;
    case SLOT_TIMER_EXPIRED:
        /*
         * Wait a little longer if we detect an incoming frame. This
         * is not mentioned in the spec, but is a good thing to do,
         * since we want to work even with devices that violate the
         * timing requirements.
         */
        if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
            IRDA_DEBUG(2, "%s(), device is slow to answer, "
                   "waiting some more!\n", __func__);
            irlap_start_slot_timer(self, msecs_to_jiffies(10));
            self->add_wait = TRUE;
            return ret;
        }
        self->add_wait = FALSE;

        if (self->s < self->S) {
            irlap_send_discovery_xid_frame(self, self->S,
                               self->s, TRUE,
                               self->discovery_cmd);
            self->s++;
            irlap_start_slot_timer(self, self->slot_timeout);

            /* Keep state */
            irlap_next_state(self, LAP_QUERY);
        } else {
            /* This is the final slot! */
            irlap_send_discovery_xid_frame(self, self->S, 0xff,
                               TRUE,
                               self->discovery_cmd);

            /* Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);

            /*
             *  We are now finished with the discovery procedure,
             *  so now we must return the results
             */
            irlap_discovery_confirm(self, self->discovery_log);

            /* IrLMP should now have taken care of the log */
            self->discovery_log = NULL;
        }
        break;
    default:
        IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
               irlap_event[event]);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_reply (self, event, skb, info)
 *
 *    REPLY, we have received a XID discovery frame from a device and we
 *    are waiting for the right time slot to send a response XID frame
 *
 */
static int irlap_state_reply(struct irlap_cb *self, IRLAP_EVENT event,
                 struct sk_buff *skb, struct irlap_info *info)
{
    discovery_t *discovery_rsp;
    int ret=0;

    IRDA_DEBUG(4, "%s()\n", __func__);

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case QUERY_TIMER_EXPIRED:
        IRDA_DEBUG(0, "%s(), QUERY_TIMER_EXPIRED <%ld>\n",
               __func__, jiffies);
        irlap_next_state(self, LAP_NDM);
        break;
    case RECV_DISCOVERY_XID_CMD:
        IRDA_ASSERT(info != NULL, return -1;);
        /* Last frame? */
        if (info->s == 0xff) {
            del_timer(&self->query_timer);

            /* info->log.condition = REMOTE; */

            /* Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);

            irlap_discovery_indication(self, info->discovery);
        } else {
            /* If it's our slot, send our reply */
            if ((info->s >= self->slot) && (!self->frame_sent)) {
                discovery_rsp = irlmp_get_discovery_response();
                discovery_rsp->data.daddr = info->daddr;

                irlap_send_discovery_xid_frame(self, info->S,
                                   self->slot,
                                   FALSE,
                                   discovery_rsp);

                self->frame_sent = TRUE;
            }
            /* Readjust our timer to accommodate devices
             * doing faster or slower discovery than us...
             * Jean II */
            irlap_start_query_timer(self, info->S, info->s);

            /* Keep state */
            //irlap_next_state(self, LAP_REPLY);
        }
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __func__,
               event, irlap_event[event]);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_conn (event, skb, info)
 *
 *    CONN, we have received a SNRM command and is waiting for the upper
 *    layer to accept or refuse connection
 *
 */
static int irlap_state_conn(struct irlap_cb *self, IRLAP_EVENT event,
                struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    IRDA_DEBUG(4, "%s(), event=%s\n", __func__, irlap_event[ event]);

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case CONNECT_RESPONSE:
        skb_pull(skb, sizeof(struct snrm_frame));

        IRDA_ASSERT(self->netdev != NULL, return -1;);

        irlap_qos_negotiate(self, skb);

        irlap_initiate_connection_state(self);

        /*
         * Applying the parameters now will make sure we change speed
         * *after* we have sent the next frame
         */
        irlap_apply_connection_parameters(self, FALSE);

        /*
         * Sending this frame will force a speed change after it has
         * been sent (i.e. the frame will be sent at 9600).
         */
        irlap_send_ua_response_frame(self, &self->qos_rx);

#if 0
        /*
         * We are allowed to send two frames, but this may increase
         * the connect latency, so lets not do it for now.
         */
        /* This is full of good intentions, but doesn't work in
         * practice.
         * After sending the first UA response, we switch the
         * dongle to the negotiated speed, which is usually
         * different than 9600 kb/s.
         * From there, there is two solutions :
         * 1) The other end has received the first UA response :
         * it will set up the connection, move to state LAP_NRM_P,
         * and will ignore and drop the second UA response.
         * Actually, it's even worse : the other side will almost
         * immediately send a RR that will likely collide with the
         * UA response (depending on negotiated turnaround).
         * 2) The other end has not received the first UA response,
         * will stay at 9600 and will never see the second UA response.
         * Jean II */
        irlap_send_ua_response_frame(self, &self->qos_rx);
#endif

        /*
         *  The WD-timer could be set to the duration of the P-timer
         *  for this case, but it is recommended to use twice the
         *  value (note 3 IrLAP p. 60).
         */
        irlap_start_wd_timer(self, self->wd_timeout);
        irlap_next_state(self, LAP_NRM_S);

        break;
    case RECV_DISCOVERY_XID_CMD:
        IRDA_DEBUG(3, "%s(), event RECV_DISCOVER_XID_CMD!\n",
               __func__);
        irlap_next_state(self, LAP_NDM);

        break;
    case DISCONNECT_REQUEST:
        IRDA_DEBUG(0, "%s(), Disconnect request!\n", __func__);
        irlap_send_dm_frame(self);
        irlap_next_state( self, LAP_NDM);
        irlap_disconnect_indication(self, LAP_DISC_INDICATION);
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __func__,
               event, irlap_event[event]);

        ret = -1;
        break;
    }

    return ret;
}

/*
 * Function irlap_state_setup (event, skb, frame)
 *
 *    SETUP state, The local layer has transmitted a SNRM command frame to
 *    a remote peer layer and is awaiting a reply .
 *
 */
static int irlap_state_setup(struct irlap_cb *self, IRLAP_EVENT event,
                 struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    IRDA_DEBUG(4, "%s()\n", __func__);

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case FINAL_TIMER_EXPIRED:
        if (self->retry_count < self->N3) {
/*
 *  Perform random backoff, Wait a random number of time units, minimum
 *  duration half the time taken to transmitt a SNRM frame, maximum duration
 *  1.5 times the time taken to transmit a SNRM frame. So this time should
 *  between 15 msecs and 45 msecs.
 */
            irlap_start_backoff_timer(self, msecs_to_jiffies(20 +
                            (jiffies % 30)));
        } else {
            /* Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);

            irlap_disconnect_indication(self, LAP_FOUND_NONE);
        }
        break;
    case BACKOFF_TIMER_EXPIRED:
        irlap_send_snrm_frame(self, &self->qos_rx);
        irlap_start_final_timer(self, self->final_timeout);
        self->retry_count++;
        break;
    case RECV_SNRM_CMD:
        IRDA_DEBUG(4, "%s(), SNRM battle!\n", __func__);

        IRDA_ASSERT(skb != NULL, return 0;);
        IRDA_ASSERT(info != NULL, return 0;);

        /*
         *  The device with the largest device address wins the battle
         *  (both have sent a SNRM command!)
         */
        if (info &&(info->daddr > self->saddr)) {
            del_timer(&self->final_timer);
            irlap_initiate_connection_state(self);

            IRDA_ASSERT(self->netdev != NULL, return -1;);

            skb_pull(skb, sizeof(struct snrm_frame));

            irlap_qos_negotiate(self, skb);

            /* Send UA frame and then change link settings */
            irlap_apply_connection_parameters(self, FALSE);
            irlap_send_ua_response_frame(self, &self->qos_rx);

            irlap_next_state(self, LAP_NRM_S);
            irlap_connect_confirm(self, skb);

            /*
             *  The WD-timer could be set to the duration of the
             *  P-timer for this case, but it is recommended
             *  to use twice the value (note 3 IrLAP p. 60).
             */
            irlap_start_wd_timer(self, self->wd_timeout);
        } else {
            /* We just ignore the other device! */
            irlap_next_state(self, LAP_SETUP);
        }
        break;
    case RECV_UA_RSP:
        /* Stop F-timer */
        del_timer(&self->final_timer);

        /* Initiate connection state */
        irlap_initiate_connection_state(self);

        /* Negotiate connection parameters */
        IRDA_ASSERT(skb->len > 10, return -1;);

        skb_pull(skb, sizeof(struct ua_frame));

        IRDA_ASSERT(self->netdev != NULL, return -1;);

        irlap_qos_negotiate(self, skb);

        /* Set the new link setting *now* (before the rr frame) */
        irlap_apply_connection_parameters(self, TRUE);
        self->retry_count = 0;

        /* Wait for turnaround time to give a chance to the other
         * device to be ready to receive us.
         * Note : the time to switch speed is typically larger
         * than the turnaround time, but as we don't have the other
         * side speed switch time, that's our best guess...
         * Jean II */
        irlap_wait_min_turn_around(self, &self->qos_tx);

        /* This frame will actually be sent at the new speed */
        irlap_send_rr_frame(self, CMD_FRAME);

        /* The timer is set to half the normal timer to quickly
         * detect a failure to negotiate the new connection
         * parameters. IrLAP 6.11.3.2, note 3.
         * Note that currently we don't process this failure
         * properly, as we should do a quick disconnect.
         * Jean II */
        irlap_start_final_timer(self, self->final_timeout/2);
        irlap_next_state(self, LAP_NRM_P);

        irlap_connect_confirm(self, skb);
        break;
    case RECV_DM_RSP:     /* FALLTHROUGH */
    case RECV_DISC_CMD:
        del_timer(&self->final_timer);
        irlap_next_state(self, LAP_NDM);

        irlap_disconnect_indication(self, LAP_DISC_INDICATION);
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __func__,
               event, irlap_event[event]);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_offline (self, event, skb, info)
 *
 *    OFFLINE state, not used for now!
 *
 */
static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb, struct irlap_info *info)
{
    IRDA_DEBUG( 0, "%s(), Unknown event\n", __func__);

    return -1;
}

/*
 * Function irlap_state_xmit_p (self, event, skb, info)
 *
 *    XMIT, Only the primary station has right to transmit, and we
 *    therefore do not expect to receive any transmissions from other
 *    stations.
 *
 */
static int irlap_state_xmit_p(struct irlap_cb *self, IRLAP_EVENT event,
                  struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    switch (event) {
    case SEND_I_CMD:
        /*
         *  Only send frame if send-window > 0.
         */
        if ((self->window > 0) && (!self->remote_busy)) {
            int nextfit;
#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
            struct sk_buff *skb_next;

            /* With DYNAMIC_WINDOW, we keep the window size
             * maximum, and adapt on the packets we are sending.
             * At 115k, we can send only 2 packets of 2048 bytes
             * in a 500 ms turnaround. Without this option, we
             * would always limit the window to 2. With this
             * option, if we send smaller packets, we can send
             * up to 7 of them (always depending on QoS).
             * Jean II */

            /* Look at the next skb. This is safe, as we are
             * the only consumer of the Tx queue (if we are not,
             * we have other problems) - Jean II */
            skb_next = skb_peek(&self->txq);

            /* Check if a subsequent skb exist and would fit in
             * the current window (with respect to turnaround
             * time).
             * This allow us to properly mark the current packet
             * with the pf bit, to avoid falling back on the
             * second test below, and avoid waiting the
             * end of the window and sending a extra RR.
             * Note : (skb_next != NULL) <=> (skb_queue_len() > 0)
             * Jean II */
            nextfit = ((skb_next != NULL) &&
                   ((skb_next->len + skb->len) <=
                    self->bytes_left));

            /*
             * The current packet may not fit ! Because of test
             * above, this should not happen any more !!!
             *  Test if we have transmitted more bytes over the
             *  link than its possible to do with the current
             *  speed and turn-around-time.
             */
            if((!nextfit) && (skb->len > self->bytes_left)) {
                IRDA_DEBUG(0, "%s(), Not allowed to transmit"
                       " more bytes!\n", __func__);
                /* Requeue the skb */
                skb_queue_head(&self->txq, skb_get(skb));
                /*
                 *  We should switch state to LAP_NRM_P, but
                 *  that is not possible since we must be sure
                 *  that we poll the other side. Since we have
                 *  used up our time, the poll timer should
                 *  trigger anyway now, so we just wait for it
                 *  DB
                 */
                /*
                 * Sorry, but that's not totally true. If
                 * we send 2000B packets, we may wait another
                 * 1000B until our turnaround expire. That's
                 * why we need to be proactive in avoiding
                 * coming here. - Jean II
                 */
                return -EPROTO;
            }

            /* Subtract space used by this skb */
            self->bytes_left -= skb->len;
#else   /* CONFIG_IRDA_DYNAMIC_WINDOW */
            /* Window has been adjusted for the max packet
             * size, so much simpler... - Jean II */
            nextfit = !skb_queue_empty(&self->txq);
#endif  /* CONFIG_IRDA_DYNAMIC_WINDOW */
            /*
             *  Send data with poll bit cleared only if window > 1
             *  and there is more frames after this one to be sent
             */
            if ((self->window > 1) && (nextfit)) {
                /* More packet to send in current window */
                irlap_send_data_primary(self, skb);
                irlap_next_state(self, LAP_XMIT_P);
            } else {
                /* Final packet of window */
                irlap_send_data_primary_poll(self, skb);

                /*
                 * Make sure state machine does not try to send
                 * any more frames
                 */
                ret = -EPROTO;
            }
#ifdef CONFIG_IRDA_FAST_RR
            /* Peer may want to reply immediately */
            self->fast_RR = FALSE;
#endif /* CONFIG_IRDA_FAST_RR */
        } else {
            IRDA_DEBUG(4, "%s(), Unable to send! remote busy?\n",
                   __func__);
            skb_queue_head(&self->txq, skb_get(skb));

            /*
             *  The next ret is important, because it tells
             *  irlap_next_state _not_ to deliver more frames
             */
            ret = -EPROTO;
        }
        break;
    case POLL_TIMER_EXPIRED:
        IRDA_DEBUG(3, "%s(), POLL_TIMER_EXPIRED <%ld>\n",
                __func__, jiffies);
        irlap_send_rr_frame(self, CMD_FRAME);
        /* Return to NRM properly - Jean II  */
        self->window = self->window_size;
#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
        /* Allowed to transmit a maximum number of bytes again. */
        self->bytes_left = self->line_capacity;
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
        irlap_start_final_timer(self, self->final_timeout);
        irlap_next_state(self, LAP_NRM_P);
        break;
    case DISCONNECT_REQUEST:
        del_timer(&self->poll_timer);
        irlap_wait_min_turn_around(self, &self->qos_tx);
        irlap_send_disc_frame(self);
        irlap_flush_all_queues(self);
        irlap_start_final_timer(self, self->final_timeout);
        self->retry_count = 0;
        irlap_next_state(self, LAP_PCLOSE);
        break;
    case DATA_REQUEST:
        /* Nothing to do, irlap_do_event() will send the packet
         * when we return... - Jean II */
        break;
    default:
        IRDA_DEBUG(0, "%s(), Unknown event %s\n",
               __func__, irlap_event[event]);

        ret = -EINVAL;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_pclose (event, skb, info)
 *
 *    PCLOSE state
 */
static int irlap_state_pclose(struct irlap_cb *self, IRLAP_EVENT event,
                  struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    IRDA_DEBUG(1, "%s()\n", __func__);

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case RECV_UA_RSP: /* FALLTHROUGH */
    case RECV_DM_RSP:
        del_timer(&self->final_timer);

        /* Set new link parameters */
        irlap_apply_default_connection_parameters(self);

        /* Always switch state before calling upper layers */
        irlap_next_state(self, LAP_NDM);

        irlap_disconnect_indication(self, LAP_DISC_INDICATION);
        break;
    case FINAL_TIMER_EXPIRED:
        if (self->retry_count < self->N3) {
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_disc_frame(self);
            irlap_start_final_timer(self, self->final_timeout);
            self->retry_count++;
            /* Keep state */
        } else {
            irlap_apply_default_connection_parameters(self);

            /*  Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);

            irlap_disconnect_indication(self, LAP_NO_RESPONSE);
        }
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %d\n", __func__, event);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_nrm_p (self, event, skb, info)
 *
 *   NRM_P (Normal Response Mode as Primary), The primary station has given
 *   permissions to a secondary station to transmit IrLAP resonse frames
 *   (by sending a frame with the P bit set). The primary station will not
 *   transmit any frames and is expecting to receive frames only from the
 *   secondary to which transmission permissions has been given.
 */
static int irlap_state_nrm_p(struct irlap_cb *self, IRLAP_EVENT event,
                 struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;
    int ns_status;
    int nr_status;

    switch (event) {
    case RECV_I_RSP: /* Optimize for the common case */
        if (unlikely(skb->len <= LAP_ADDR_HEADER + LAP_CTRL_HEADER)) {
            /*
             * Input validation check: a stir4200/mcp2150
             * combination sometimes results in an empty i:rsp.
             * This makes no sense; we can just ignore the frame
             * and send an rr:cmd immediately. This happens before
             * changing nr or ns so triggers a retransmit
             */
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_rr_frame(self, CMD_FRAME);
            /* Keep state */
            break;
        }
        /* FIXME: must check for remote_busy below */
#ifdef CONFIG_IRDA_FAST_RR
        /*
         *  Reset the fast_RR so we can use the fast RR code with
         *  full speed the next time since peer may have more frames
         *  to transmitt
         */
        self->fast_RR = FALSE;
#endif /* CONFIG_IRDA_FAST_RR */
        IRDA_ASSERT( info != NULL, return -1;);

        ns_status = irlap_validate_ns_received(self, info->ns);
        nr_status = irlap_validate_nr_received(self, info->nr);

        /*
         *  Check for expected I(nformation) frame
         */
        if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {

            /* Update Vr (next frame for us to receive) */
            self->vr = (self->vr + 1) % 8;

            /* Update Nr received, cleanup our retry queue */
            irlap_update_nr_received(self, info->nr);

            /*
             *  Got expected NR, so reset the
             *  retry_count. This is not done by IrLAP spec,
             *  which is strange!
             */
            self->retry_count = 0;
            self->ack_required = TRUE;

            /*  poll bit cleared?  */
            if (!info->pf) {
                /* Keep state, do not move this line */
                irlap_next_state(self, LAP_NRM_P);

                irlap_data_indication(self, skb, FALSE);
            } else {
                /* No longer waiting for pf */
                del_timer(&self->final_timer);

                irlap_wait_min_turn_around(self, &self->qos_tx);

                /* Call higher layer *before* changing state
                 * to give them a chance to send data in the
                 * next LAP frame.
                 * Jean II */
                irlap_data_indication(self, skb, FALSE);

                /* XMIT states are the most dangerous state
                 * to be in, because user requests are
                 * processed directly and may change state.
                 * On the other hand, in NDM_P, those
                 * requests are queued and we will process
                 * them when we return to irlap_do_event().
                 * Jean II
                 */
                irlap_next_state(self, LAP_XMIT_P);

                /* This is the last frame.
                 * Make sure it's always called in XMIT state.
                 * - Jean II */
                irlap_start_poll_timer(self, self->poll_timeout);
            }
            break;

        }
        /* Unexpected next to send (Ns) */
        if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
        {
            if (!info->pf) {
                irlap_update_nr_received(self, info->nr);

                /*
                 *  Wait until the last frame before doing
                 *  anything
                 */

                /* Keep state */
                irlap_next_state(self, LAP_NRM_P);
            } else {
                IRDA_DEBUG(4,
                       "%s(), missing or duplicate frame!\n",
                       __func__);

                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);

                irlap_wait_min_turn_around(self, &self->qos_tx);
                irlap_send_rr_frame(self, CMD_FRAME);

                self->ack_required = FALSE;

                irlap_start_final_timer(self, self->final_timeout);
                irlap_next_state(self, LAP_NRM_P);
            }
            break;
        }
        /*
         *  Unexpected next to receive (Nr)
         */
        if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
        {
            if (info->pf) {
                self->vr = (self->vr + 1) % 8;

                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);

                /* Resend rejected frames */
                irlap_resend_rejected_frames(self, CMD_FRAME);

                self->ack_required = FALSE;

                /* Make sure we account for the time
                 * to transmit our frames. See comemnts
                 * in irlap_send_data_primary_poll().
                 * Jean II */
                irlap_start_final_timer(self, 2 * self->final_timeout);

                /* Keep state, do not move this line */
                irlap_next_state(self, LAP_NRM_P);

                irlap_data_indication(self, skb, FALSE);
            } else {
                /*
                 *  Do not resend frames until the last
                 *  frame has arrived from the other
                 *  device. This is not documented in
                 *  IrLAP!!
                 */
                self->vr = (self->vr + 1) % 8;

                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);

                self->ack_required = FALSE;

                /* Keep state, do not move this line!*/
                irlap_next_state(self, LAP_NRM_P);

                irlap_data_indication(self, skb, FALSE);
            }
            break;
        }
        /*
         *  Unexpected next to send (Ns) and next to receive (Nr)
         *  Not documented by IrLAP!
         */
        if ((ns_status == NS_UNEXPECTED) &&
            (nr_status == NR_UNEXPECTED))
        {
            IRDA_DEBUG(4, "%s(), unexpected nr and ns!\n",
                   __func__);
            if (info->pf) {
                /* Resend rejected frames */
                irlap_resend_rejected_frames(self, CMD_FRAME);

                /* Give peer some time to retransmit!
                 * But account for our own Tx. */
                irlap_start_final_timer(self, 2 * self->final_timeout);

                /* Keep state, do not move this line */
                irlap_next_state(self, LAP_NRM_P);
            } else {
                /* Update Nr received */
                /* irlap_update_nr_received( info->nr); */

                self->ack_required = FALSE;
            }
            break;
        }

        /*
         *  Invalid NR or NS
         */
        if ((nr_status == NR_INVALID) || (ns_status == NS_INVALID)) {
            if (info->pf) {
                del_timer(&self->final_timer);

                irlap_next_state(self, LAP_RESET_WAIT);

                irlap_disconnect_indication(self, LAP_RESET_INDICATION);
                self->xmitflag = TRUE;
            } else {
                del_timer(&self->final_timer);

                irlap_disconnect_indication(self, LAP_RESET_INDICATION);

                self->xmitflag = FALSE;
            }
            break;
        }
        IRDA_DEBUG(1, "%s(), Not implemented!\n", __func__);
        IRDA_DEBUG(1, "%s(), event=%s, ns_status=%d, nr_status=%d\n",
               __func__, irlap_event[event], ns_status, nr_status);
        break;
    case RECV_UI_FRAME:
        /* Poll bit cleared? */
        if (!info->pf) {
            irlap_data_indication(self, skb, TRUE);
            irlap_next_state(self, LAP_NRM_P);
        } else {
            del_timer(&self->final_timer);
            irlap_data_indication(self, skb, TRUE);
            irlap_next_state(self, LAP_XMIT_P);
            IRDA_DEBUG(1, "%s: RECV_UI_FRAME: next state %s\n", __func__, irlap_state[self->state]);
            irlap_start_poll_timer(self, self->poll_timeout);
        }
        break;
    case RECV_RR_RSP:
        /*
         *  If you get a RR, the remote isn't busy anymore,
         *  no matter what the NR
         */
        self->remote_busy = FALSE;

        /* Stop final timer */
        del_timer(&self->final_timer);

        /*
         *  Nr as expected?
         */
        ret = irlap_validate_nr_received(self, info->nr);
        if (ret == NR_EXPECTED) {
            /* Update Nr received */
            irlap_update_nr_received(self, info->nr);

            /*
             *  Got expected NR, so reset the retry_count. This
             *  is not done by the IrLAP standard , which is
             *  strange! DB.
             */
            self->retry_count = 0;
            irlap_wait_min_turn_around(self, &self->qos_tx);

            irlap_next_state(self, LAP_XMIT_P);

            /* Start poll timer */
            irlap_start_poll_timer(self, self->poll_timeout);
        } else if (ret == NR_UNEXPECTED) {
            IRDA_ASSERT(info != NULL, return -1;);
            /*
             *  Unexpected nr!
             */

            /* Update Nr received */
            irlap_update_nr_received(self, info->nr);

            IRDA_DEBUG(4, "RECV_RR_FRAME: Retrans:%d, nr=%d, va=%d, "
                  "vs=%d, vr=%d\n",
                  self->retry_count, info->nr, self->va,
                  self->vs, self->vr);

            /* Resend rejected frames */
            irlap_resend_rejected_frames(self, CMD_FRAME);
            irlap_start_final_timer(self, self->final_timeout * 2);

            irlap_next_state(self, LAP_NRM_P);
        } else if (ret == NR_INVALID) {
            IRDA_DEBUG(1, "%s(), Received RR with "
                   "invalid nr !\n", __func__);

            irlap_next_state(self, LAP_RESET_WAIT);

            irlap_disconnect_indication(self, LAP_RESET_INDICATION);
            self->xmitflag = TRUE;
        }
        break;
    case RECV_RNR_RSP:
        IRDA_ASSERT(info != NULL, return -1;);

        /* Stop final timer */
        del_timer(&self->final_timer);
        self->remote_busy = TRUE;

        /* Update Nr received */
        irlap_update_nr_received(self, info->nr);
        irlap_next_state(self, LAP_XMIT_P);

        /* Start poll timer */
        irlap_start_poll_timer(self, self->poll_timeout);
        break;
    case RECV_FRMR_RSP:
        del_timer(&self->final_timer);
        self->xmitflag = TRUE;
        irlap_next_state(self, LAP_RESET_WAIT);
        irlap_reset_indication(self);
        break;
    case FINAL_TIMER_EXPIRED:
        /*
         *  We are allowed to wait for additional 300 ms if
         *  final timer expires when we are in the middle
         *  of receiving a frame (page 45, IrLAP). Check that
         *  we only do this once for each frame.
         */
        if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
            IRDA_DEBUG(1, "FINAL_TIMER_EXPIRED when receiving a "
                  "frame! Waiting a little bit more!\n");
            irlap_start_final_timer(self, msecs_to_jiffies(300));

            /*
             *  Don't allow this to happen one more time in a row,
             *  or else we can get a pretty tight loop here if
             *  if we only receive half a frame. DB.
             */
            self->add_wait = TRUE;
            break;
        }
        self->add_wait = FALSE;

        /* N2 is the disconnect timer. Until we reach it, we retry */
        if (self->retry_count < self->N2) {
            if (skb_peek(&self->wx_list) == NULL) {
                /* Retry sending the pf bit to the secondary */
                IRDA_DEBUG(4, "nrm_p: resending rr");
                irlap_wait_min_turn_around(self, &self->qos_tx);
                irlap_send_rr_frame(self, CMD_FRAME);
            } else {
                IRDA_DEBUG(4, "nrm_p: resend frames");
                irlap_resend_rejected_frames(self, CMD_FRAME);
            }

            irlap_start_final_timer(self, self->final_timeout);
            self->retry_count++;
            IRDA_DEBUG(4, "irlap_state_nrm_p: FINAL_TIMER_EXPIRED:"
                   " retry_count=%d\n", self->retry_count);

            /* Early warning event. I'm using a pretty liberal
             * interpretation of the spec and generate an event
             * every time the timer is multiple of N1 (and not
             * only the first time). This allow application
             * to know precisely if connectivity restart...
             * Jean II */
            if((self->retry_count % self->N1) == 0)
                irlap_status_indication(self,
                            STATUS_NO_ACTIVITY);

            /* Keep state */
        } else {
            irlap_apply_default_connection_parameters(self);

            /* Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);
            irlap_disconnect_indication(self, LAP_NO_RESPONSE);
        }
        break;
    case RECV_REJ_RSP:
        irlap_update_nr_received(self, info->nr);
        if (self->remote_busy) {
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_rr_frame(self, CMD_FRAME);
        } else
            irlap_resend_rejected_frames(self, CMD_FRAME);
        irlap_start_final_timer(self, 2 * self->final_timeout);
        break;
    case RECV_SREJ_RSP:
        irlap_update_nr_received(self, info->nr);
        if (self->remote_busy) {
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_rr_frame(self, CMD_FRAME);
        } else
            irlap_resend_rejected_frame(self, CMD_FRAME);
        irlap_start_final_timer(self, 2 * self->final_timeout);
        break;
    case RECV_RD_RSP:
        IRDA_DEBUG(1, "%s(), RECV_RD_RSP\n", __func__);

        irlap_flush_all_queues(self);
        irlap_next_state(self, LAP_XMIT_P);
        /* Call back the LAP state machine to do a proper disconnect */
        irlap_disconnect_request(self);
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %s\n",
                __func__, irlap_event[event]);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_reset_wait (event, skb, info)
 *
 *    We have informed the service user of a reset condition, and is
 *    awaiting reset of disconnect request.
 *
 */
static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
                  struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    IRDA_DEBUG(3, "%s(), event = %s\n", __func__, irlap_event[event]);

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case RESET_REQUEST:
        if (self->xmitflag) {
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_snrm_frame(self, NULL);
            irlap_start_final_timer(self, self->final_timeout);
            irlap_next_state(self, LAP_RESET);
        } else {
            irlap_start_final_timer(self, self->final_timeout);
            irlap_next_state(self, LAP_RESET);
        }
        break;
    case DISCONNECT_REQUEST:
        irlap_wait_min_turn_around( self, &self->qos_tx);
        irlap_send_disc_frame( self);
        irlap_flush_all_queues( self);
        irlap_start_final_timer( self, self->final_timeout);
        self->retry_count = 0;
        irlap_next_state( self, LAP_PCLOSE);
        break;
    default:
        IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
               irlap_event[event]);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_reset (self, event, skb, info)
 *
 *    We have sent a SNRM reset command to the peer layer, and is awaiting
 *    reply.
 *
 */
static int irlap_state_reset(struct irlap_cb *self, IRLAP_EVENT event,
                 struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    IRDA_DEBUG(3, "%s(), event = %s\n", __func__, irlap_event[event]);

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case RECV_DISC_CMD:
        del_timer(&self->final_timer);

        irlap_apply_default_connection_parameters(self);

        /* Always switch state before calling upper layers */
        irlap_next_state(self, LAP_NDM);

        irlap_disconnect_indication(self, LAP_NO_RESPONSE);

        break;
    case RECV_UA_RSP:
        del_timer(&self->final_timer);

        /* Initiate connection state */
        irlap_initiate_connection_state(self);

        irlap_reset_confirm();

        self->remote_busy = FALSE;

        irlap_next_state(self, LAP_XMIT_P);

        irlap_start_poll_timer(self, self->poll_timeout);

        break;
    case FINAL_TIMER_EXPIRED:
        if (self->retry_count < 3) {
            irlap_wait_min_turn_around(self, &self->qos_tx);

            IRDA_ASSERT(self->netdev != NULL, return -1;);
            irlap_send_snrm_frame(self, self->qos_dev);

            self->retry_count++; /* Experimental!! */

            irlap_start_final_timer(self, self->final_timeout);
            irlap_next_state(self, LAP_RESET);
        } else if (self->retry_count >= self->N3) {
            irlap_apply_default_connection_parameters(self);

            /* Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);

            irlap_disconnect_indication(self, LAP_NO_RESPONSE);
        }
        break;
    case RECV_SNRM_CMD:
        /*
         * SNRM frame is not allowed to contain an I-field in this
         * state
         */
        if (!info) {
            IRDA_DEBUG(3, "%s(), RECV_SNRM_CMD\n", __func__);
            irlap_initiate_connection_state(self);
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_ua_response_frame(self, &self->qos_rx);
            irlap_reset_confirm();
            irlap_start_wd_timer(self, self->wd_timeout);
            irlap_next_state(self, LAP_NDM);
        } else {
            IRDA_DEBUG(0,
                   "%s(), SNRM frame contained an I field!\n",
                   __func__);
        }
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %s\n",
               __func__, irlap_event[event]);

        ret = -1;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_xmit_s (event, skb, info)
 *
 *   XMIT_S, The secondary station has been given the right to transmit,
 *   and we therefore do not expect to receive any transmissions from other
 *   stations.
 */
static int irlap_state_xmit_s(struct irlap_cb *self, IRLAP_EVENT event,
                  struct sk_buff *skb, struct irlap_info *info)
{
    int ret = 0;

    IRDA_DEBUG(4, "%s(), event=%s\n", __func__, irlap_event[event]);

    IRDA_ASSERT(self != NULL, return -ENODEV;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);

    switch (event) {
    case SEND_I_CMD:
        /*
         *  Send frame only if send window > 0
         */
        if ((self->window > 0) && (!self->remote_busy)) {
            int nextfit;
#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
            struct sk_buff *skb_next;

            /*
             * Same deal as in irlap_state_xmit_p(), so see
             * the comments at that point.
             * We are the secondary, so there are only subtle
             * differences. - Jean II
             */

            /* Check if a subsequent skb exist and would fit in
             * the current window (with respect to turnaround
             * time). - Jean II */
            skb_next = skb_peek(&self->txq);
            nextfit = ((skb_next != NULL) &&
                   ((skb_next->len + skb->len) <=
                    self->bytes_left));

            /*
             *  Test if we have transmitted more bytes over the
             *  link than its possible to do with the current
             *  speed and turn-around-time.
             */
            if((!nextfit) && (skb->len > self->bytes_left)) {
                IRDA_DEBUG(0, "%s(), Not allowed to transmit"
                       " more bytes!\n", __func__);
                /* Requeue the skb */
                skb_queue_head(&self->txq, skb_get(skb));

                /*
                 *  Switch to NRM_S, this is only possible
                 *  when we are in secondary mode, since we
                 *  must be sure that we don't miss any RR
                 *  frames
                 */
                self->window = self->window_size;
                self->bytes_left = self->line_capacity;
                irlap_start_wd_timer(self, self->wd_timeout);

                irlap_next_state(self, LAP_NRM_S);
                /* Slight difference with primary :
                 * here we would wait for the other side to
                 * expire the turnaround. - Jean II */

                return -EPROTO; /* Try again later */
            }
            /* Subtract space used by this skb */
            self->bytes_left -= skb->len;
#else   /* CONFIG_IRDA_DYNAMIC_WINDOW */
            /* Window has been adjusted for the max packet
             * size, so much simpler... - Jean II */
            nextfit = !skb_queue_empty(&self->txq);
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
            /*
             *  Send data with final bit cleared only if window > 1
             *  and there is more frames to be sent
             */
            if ((self->window > 1) && (nextfit)) {
                irlap_send_data_secondary(self, skb);
                irlap_next_state(self, LAP_XMIT_S);
            } else {
                irlap_send_data_secondary_final(self, skb);
                irlap_next_state(self, LAP_NRM_S);

                /*
                 * Make sure state machine does not try to send
                 * any more frames
                 */
                ret = -EPROTO;
            }
        } else {
            IRDA_DEBUG(2, "%s(), Unable to send!\n", __func__);
            skb_queue_head(&self->txq, skb_get(skb));
            ret = -EPROTO;
        }
        break;
    case DISCONNECT_REQUEST:
        irlap_send_rd_frame(self);
        irlap_flush_all_queues(self);
        irlap_start_wd_timer(self, self->wd_timeout);
        irlap_next_state(self, LAP_SCLOSE);
        break;
    case DATA_REQUEST:
        /* Nothing to do, irlap_do_event() will send the packet
         * when we return... - Jean II */
        break;
    default:
        IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
               irlap_event[event]);

        ret = -EINVAL;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_nrm_s (event, skb, info)
 *
 *    NRM_S (Normal Response Mode as Secondary) state, in this state we are
 *    expecting to receive frames from the primary station
 *
 */
static int irlap_state_nrm_s(struct irlap_cb *self, IRLAP_EVENT event,
                 struct sk_buff *skb, struct irlap_info *info)
{
    int ns_status;
    int nr_status;
    int ret = 0;

    IRDA_DEBUG(4, "%s(), event=%s\n", __func__, irlap_event[ event]);

    IRDA_ASSERT(self != NULL, return -1;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);

    switch (event) {
    case RECV_I_CMD: /* Optimize for the common case */
        /* FIXME: must check for remote_busy below */
        IRDA_DEBUG(4, "%s(), event=%s nr=%d, vs=%d, ns=%d, "
               "vr=%d, pf=%d\n", __func__,
               irlap_event[event], info->nr,
               self->vs, info->ns, self->vr, info->pf);

        self->retry_count = 0;

        ns_status = irlap_validate_ns_received(self, info->ns);
        nr_status = irlap_validate_nr_received(self, info->nr);
        /*
         *  Check for expected I(nformation) frame
         */
        if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {

            /* Update Vr (next frame for us to receive) */
            self->vr = (self->vr + 1) % 8;

            /* Update Nr received */
            irlap_update_nr_received(self, info->nr);

            /*
             *  poll bit cleared?
             */
            if (!info->pf) {

                self->ack_required = TRUE;

                /*
                 *  Starting WD-timer here is optional, but
                 *  not recommended. Note 6 IrLAP p. 83
                 */
#if 0
                irda_start_timer(WD_TIMER, self->wd_timeout);
#endif
                /* Keep state, do not move this line */
                irlap_next_state(self, LAP_NRM_S);

                irlap_data_indication(self, skb, FALSE);
                break;
            } else {
                /*
                 *  We should wait before sending RR, and
                 *  also before changing to XMIT_S
                 *  state. (note 1, IrLAP p. 82)
                 */
                irlap_wait_min_turn_around(self, &self->qos_tx);

                /*
                 * Give higher layers a chance to
                 * immediately reply with some data before
                 * we decide if we should send a RR frame
                 * or not
                 */
                irlap_data_indication(self, skb, FALSE);

                /* Any pending data requests?  */
                if (!skb_queue_empty(&self->txq) &&
                    (self->window > 0))
                {
                    self->ack_required = TRUE;

                    del_timer(&self->wd_timer);

                    irlap_next_state(self, LAP_XMIT_S);
                } else {
                    irlap_send_rr_frame(self, RSP_FRAME);
                    irlap_start_wd_timer(self,
                                 self->wd_timeout);

                    /* Keep the state */
                    irlap_next_state(self, LAP_NRM_S);
                }
                break;
            }
        }
        /*
         *  Check for Unexpected next to send (Ns)
         */
        if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
        {
            /* Unexpected next to send, with final bit cleared */
            if (!info->pf) {
                irlap_update_nr_received(self, info->nr);

                irlap_start_wd_timer(self, self->wd_timeout);
            } else {
                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);

                irlap_wait_min_turn_around(self, &self->qos_tx);
                irlap_send_rr_frame(self, RSP_FRAME);

                irlap_start_wd_timer(self, self->wd_timeout);
            }
            break;
        }

        /*
         *  Unexpected Next to Receive(NR) ?
         */
        if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
        {
            if (info->pf) {
                IRDA_DEBUG(4, "RECV_I_RSP: frame(s) lost\n");

                self->vr = (self->vr + 1) % 8;

                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);

                /* Resend rejected frames */
                irlap_resend_rejected_frames(self, RSP_FRAME);

                /* Keep state, do not move this line */
                irlap_next_state(self, LAP_NRM_S);

                irlap_data_indication(self, skb, FALSE);
                irlap_start_wd_timer(self, self->wd_timeout);
                break;
            }
            /*
             *  This is not documented in IrLAP!! Unexpected NR
             *  with poll bit cleared
             */
            if (!info->pf) {
                self->vr = (self->vr + 1) % 8;

                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);

                /* Keep state, do not move this line */
                irlap_next_state(self, LAP_NRM_S);

                irlap_data_indication(self, skb, FALSE);
                irlap_start_wd_timer(self, self->wd_timeout);
            }
            break;
        }

        if (ret == NR_INVALID) {
            IRDA_DEBUG(0, "NRM_S, NR_INVALID not implemented!\n");
        }
        if (ret == NS_INVALID) {
            IRDA_DEBUG(0, "NRM_S, NS_INVALID not implemented!\n");
        }
        break;
    case RECV_UI_FRAME:
        /*
         *  poll bit cleared?
         */
        if (!info->pf) {
            irlap_data_indication(self, skb, TRUE);
            irlap_next_state(self, LAP_NRM_S); /* Keep state */
        } else {
            /*
             *  Any pending data requests?
             */
            if (!skb_queue_empty(&self->txq) &&
                (self->window > 0) && !self->remote_busy)
            {
                irlap_data_indication(self, skb, TRUE);

                del_timer(&self->wd_timer);

                irlap_next_state(self, LAP_XMIT_S);
            } else {
                irlap_data_indication(self, skb, TRUE);

                irlap_wait_min_turn_around(self, &self->qos_tx);

                irlap_send_rr_frame(self, RSP_FRAME);
                self->ack_required = FALSE;

                irlap_start_wd_timer(self, self->wd_timeout);

                /* Keep the state */
                irlap_next_state(self, LAP_NRM_S);
            }
        }
        break;
    case RECV_RR_CMD:
        self->retry_count = 0;

        /*
         *  Nr as expected?
         */
        nr_status = irlap_validate_nr_received(self, info->nr);
        if (nr_status == NR_EXPECTED) {
            if (!skb_queue_empty(&self->txq) &&
                (self->window > 0)) {
                self->remote_busy = FALSE;

                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);
                del_timer(&self->wd_timer);

                irlap_wait_min_turn_around(self, &self->qos_tx);
                irlap_next_state(self, LAP_XMIT_S);
            } else {
                self->remote_busy = FALSE;
                /* Update Nr received */
                irlap_update_nr_received(self, info->nr);
                irlap_wait_min_turn_around(self, &self->qos_tx);
                irlap_start_wd_timer(self, self->wd_timeout);

                /* Note : if the link is idle (this case),
                 * we never go in XMIT_S, so we never get a
                 * chance to process any DISCONNECT_REQUEST.
                 * Do it now ! - Jean II */
                if (self->disconnect_pending) {
                    /* Disconnect */
                    irlap_send_rd_frame(self);
                    irlap_flush_all_queues(self);

                    irlap_next_state(self, LAP_SCLOSE);
                } else {
                    /* Just send back pf bit */
                    irlap_send_rr_frame(self, RSP_FRAME);

                    irlap_next_state(self, LAP_NRM_S);
                }
            }
        } else if (nr_status == NR_UNEXPECTED) {
            self->remote_busy = FALSE;
            irlap_update_nr_received(self, info->nr);
            irlap_resend_rejected_frames(self, RSP_FRAME);

            irlap_start_wd_timer(self, self->wd_timeout);

            /* Keep state */
            irlap_next_state(self, LAP_NRM_S);
        } else {
            IRDA_DEBUG(1, "%s(), invalid nr not implemented!\n",
                   __func__);
        }
        break;
    case RECV_SNRM_CMD:
        /* SNRM frame is not allowed to contain an I-field */
        if (!info) {
            del_timer(&self->wd_timer);
            IRDA_DEBUG(1, "%s(), received SNRM cmd\n", __func__);
            irlap_next_state(self, LAP_RESET_CHECK);

            irlap_reset_indication(self);
        } else {
            IRDA_DEBUG(0,
                   "%s(), SNRM frame contained an I-field!\n",
                   __func__);

        }
        break;
    case RECV_REJ_CMD:
        irlap_update_nr_received(self, info->nr);
        if (self->remote_busy) {
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_rr_frame(self, RSP_FRAME);
        } else
            irlap_resend_rejected_frames(self, RSP_FRAME);
        irlap_start_wd_timer(self, self->wd_timeout);
        break;
    case RECV_SREJ_CMD:
        irlap_update_nr_received(self, info->nr);
        if (self->remote_busy) {
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_rr_frame(self, RSP_FRAME);
        } else
            irlap_resend_rejected_frame(self, RSP_FRAME);
        irlap_start_wd_timer(self, self->wd_timeout);
        break;
    case WD_TIMER_EXPIRED:
        /*
         *  Wait until retry_count * n matches negotiated threshold/
         *  disconnect time (note 2 in IrLAP p. 82)
         *
         * Similar to irlap_state_nrm_p() -> FINAL_TIMER_EXPIRED
         * Note : self->wd_timeout = (self->final_timeout * 2),
         *   which explain why we use (self->N2 / 2) here !!!
         * Jean II
         */
        IRDA_DEBUG(1, "%s(), retry_count = %d\n", __func__,
               self->retry_count);

        if (self->retry_count < (self->N2 / 2)) {
            /* No retry, just wait for primary */
            irlap_start_wd_timer(self, self->wd_timeout);
            self->retry_count++;

            if((self->retry_count % (self->N1 / 2)) == 0)
                irlap_status_indication(self,
                            STATUS_NO_ACTIVITY);
        } else {
            irlap_apply_default_connection_parameters(self);

            /* Always switch state before calling upper layers */
            irlap_next_state(self, LAP_NDM);
            irlap_disconnect_indication(self, LAP_NO_RESPONSE);
        }
        break;
    case RECV_DISC_CMD:
        /* Always switch state before calling upper layers */
        irlap_next_state(self, LAP_NDM);

        /* Send disconnect response */
        irlap_wait_min_turn_around(self, &self->qos_tx);
        irlap_send_ua_response_frame(self, NULL);

        del_timer(&self->wd_timer);
        irlap_flush_all_queues(self);
        /* Set default link parameters */
        irlap_apply_default_connection_parameters(self);

        irlap_disconnect_indication(self, LAP_DISC_INDICATION);
        break;
    case RECV_DISCOVERY_XID_CMD:
        irlap_wait_min_turn_around(self, &self->qos_tx);
        irlap_send_rr_frame(self, RSP_FRAME);
        self->ack_required = TRUE;
        irlap_start_wd_timer(self, self->wd_timeout);
        irlap_next_state(self, LAP_NRM_S);

        break;
    case RECV_TEST_CMD:
        /* Remove test frame header (only LAP header in NRM) */
        skb_pull(skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);

        irlap_wait_min_turn_around(self, &self->qos_tx);
        irlap_start_wd_timer(self, self->wd_timeout);

        /* Send response (info will be copied) */
        irlap_send_test_frame(self, self->caddr, info->daddr, skb);
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __func__,
               event, irlap_event[event]);

        ret = -EINVAL;
        break;
    }
    return ret;
}

/*
 * Function irlap_state_sclose (self, event, skb, info)
 */
static int irlap_state_sclose(struct irlap_cb *self, IRLAP_EVENT event,
                  struct sk_buff *skb, struct irlap_info *info)
{
    IRDA_DEBUG(1, "%s()\n", __func__);

    IRDA_ASSERT(self != NULL, return -ENODEV;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);

    switch (event) {
    case RECV_DISC_CMD:
        /* Always switch state before calling upper layers */
        irlap_next_state(self, LAP_NDM);

        /* Send disconnect response */
        irlap_wait_min_turn_around(self, &self->qos_tx);
        irlap_send_ua_response_frame(self, NULL);

        del_timer(&self->wd_timer);
        /* Set default link parameters */
        irlap_apply_default_connection_parameters(self);

        irlap_disconnect_indication(self, LAP_DISC_INDICATION);
        break;
    case RECV_DM_RSP:
        /* IrLAP-1.1 p.82: in SCLOSE, S and I type RSP frames
         * shall take us down into default NDM state, like DM_RSP
         */
    case RECV_RR_RSP:
    case RECV_RNR_RSP:
    case RECV_REJ_RSP:
    case RECV_SREJ_RSP:
    case RECV_I_RSP:
        /* Always switch state before calling upper layers */
        irlap_next_state(self, LAP_NDM);

        del_timer(&self->wd_timer);
        irlap_apply_default_connection_parameters(self);

        irlap_disconnect_indication(self, LAP_DISC_INDICATION);
        break;
    case WD_TIMER_EXPIRED:
        /* Always switch state before calling upper layers */
        irlap_next_state(self, LAP_NDM);

        irlap_apply_default_connection_parameters(self);

        irlap_disconnect_indication(self, LAP_DISC_INDICATION);
        break;
    default:
        /* IrLAP-1.1 p.82: in SCLOSE, basically any received frame
         * with pf=1 shall restart the wd-timer and resend the rd:rsp
         */
        if (info != NULL  &&  info->pf) {
            del_timer(&self->wd_timer);
            irlap_wait_min_turn_around(self, &self->qos_tx);
            irlap_send_rd_frame(self);
            irlap_start_wd_timer(self, self->wd_timeout);
            break;      /* stay in SCLOSE */
        }

        IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __func__,
               event, irlap_event[event]);

        break;
    }

    return -1;
}

static int irlap_state_reset_check( struct irlap_cb *self, IRLAP_EVENT event,
                   struct sk_buff *skb,
                   struct irlap_info *info)
{
    int ret = 0;

    IRDA_DEBUG(1, "%s(), event=%s\n", __func__, irlap_event[event]);

    IRDA_ASSERT(self != NULL, return -ENODEV;);
    IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);

    switch (event) {
    case RESET_RESPONSE:
        irlap_send_ua_response_frame(self, &self->qos_rx);
        irlap_initiate_connection_state(self);
        irlap_start_wd_timer(self, WD_TIMEOUT);
        irlap_flush_all_queues(self);

        irlap_next_state(self, LAP_NRM_S);
        break;
    case DISCONNECT_REQUEST:
        irlap_wait_min_turn_around(self, &self->qos_tx);
        irlap_send_rd_frame(self);
        irlap_start_wd_timer(self, WD_TIMEOUT);
        irlap_next_state(self, LAP_SCLOSE);
        break;
    default:
        IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __func__,
               event, irlap_event[event]);

        ret = -EINVAL;
        break;
    }
    return ret;
}