OVMS3-idf/components/bt/bluedroid/stack/l2cap/l2c_csm.c

/******************************************************************************
 *
 *  Copyright (C) 1999-2012 Broadcom Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at:
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 ******************************************************************************/

/******************************************************************************
 *
 *  This file contains the L2CAP channel state machine
 *
 ******************************************************************************/

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "bt_target.h"
#include "gki.h"
#include "hcidefs.h"
#include "hcimsgs.h"
#include "l2cdefs.h"
#include "l2c_int.h"
#include "btm_int.h"
#include "btu.h"
#include "hcimsgs.h"

/********************************************************************************/
/*              L O C A L    F U N C T I O N     P R O T O T Y P E S            */
/********************************************************************************/
static void l2c_csm_closed (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_orig_w4_sec_comp (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_term_w4_sec_comp (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_w4_l2cap_connect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_w4_l2ca_connect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_config (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_open (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_w4_l2cap_disconnect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data);
static void l2c_csm_w4_l2ca_disconnect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data);

#if (BT_TRACE_VERBOSE == TRUE)
static char *l2c_csm_get_event_name (UINT16 event);
#endif

/*******************************************************************************
**
** Function         l2c_csm_execute
**
** Description      This function executes the state machine.
**
** Returns          void
**
*******************************************************************************/
void l2c_csm_execute (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    switch (p_ccb->chnl_state) {
    case CST_CLOSED:
        l2c_csm_closed (p_ccb, event, p_data);
        break;

    case CST_ORIG_W4_SEC_COMP:
        l2c_csm_orig_w4_sec_comp (p_ccb, event, p_data);
        break;

    case CST_TERM_W4_SEC_COMP:
        l2c_csm_term_w4_sec_comp (p_ccb, event, p_data);
        break;

    case CST_W4_L2CAP_CONNECT_RSP:
        l2c_csm_w4_l2cap_connect_rsp (p_ccb, event, p_data);
        break;

    case CST_W4_L2CA_CONNECT_RSP:
        l2c_csm_w4_l2ca_connect_rsp (p_ccb, event, p_data);
        break;

    case CST_CONFIG:
        l2c_csm_config (p_ccb, event, p_data);
        break;

    case CST_OPEN:
        l2c_csm_open (p_ccb, event, p_data);
        break;

    case CST_W4_L2CAP_DISCONNECT_RSP:
        l2c_csm_w4_l2cap_disconnect_rsp (p_ccb, event, p_data);
        break;

    case CST_W4_L2CA_DISCONNECT_RSP:
        l2c_csm_w4_l2ca_disconnect_rsp (p_ccb, event, p_data);
        break;

    default:
        L2CAP_TRACE_DEBUG("Unhandled event! event = %d", event);
        break;
    }
}

/*******************************************************************************
**
** Function         l2c_csm_closed
**
** Description      This function handles events when the channel is in
**                  CLOSED state. This state exists only when the link is
**                  being initially established.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_closed (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    tL2C_CONN_INFO          *p_ci = (tL2C_CONN_INFO *)p_data;
    UINT16                  local_cid = p_ccb->local_cid;
    tL2CA_DISCONNECT_IND_CB *disconnect_ind;
    tL2CA_CONNECT_CFM_CB    *connect_cfm;

    if (p_ccb->p_rcb == NULL) {
#if (BT_TRACE_VERBOSE == TRUE)
        L2CAP_TRACE_ERROR ("L2CAP - LCID: 0x%04x  st: CLOSED  evt: %s p_rcb == NULL", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
        L2CAP_TRACE_ERROR ("L2CAP - LCID: 0x%04x  st: CLOSED  evt: 0x%04x p_rcb == NULL", p_ccb->local_cid, event);
#endif
        return;
    }

#if (L2CAP_UCD_INCLUDED == TRUE)
    if ( local_cid == L2CAP_CONNECTIONLESS_CID ) {
        /* check if this event can be processed by UCD */
        if ( l2c_ucd_process_event (p_ccb, event, p_data) ) {
            /* The event is processed by UCD state machine */
            return;
        }
    }
#endif

    disconnect_ind = p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb;
    connect_cfm    = p_ccb->p_rcb->api.pL2CA_ConnectCfm_Cb;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: CLOSED  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: CLOSED evt: %d", event);
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;

    case L2CEVT_LP_CONNECT_CFM:                         /* Link came up         */
        p_ccb->chnl_state = CST_ORIG_W4_SEC_COMP;
        btm_sec_l2cap_access_req (p_ccb->p_lcb->remote_bd_addr, p_ccb->p_rcb->psm,
                                  p_ccb->p_lcb->handle, TRUE, &l2c_link_sec_comp, p_ccb);
        break;

    case L2CEVT_LP_CONNECT_CFM_NEG:                     /* Link failed          */
        /* Disconnect unless ACL collision and upper layer wants to handle it */
        if (p_ci->status != HCI_ERR_CONNECTION_EXISTS
                || !btm_acl_notif_conn_collision(p_ccb->p_lcb->remote_bd_addr)) {
            L2CAP_TRACE_API ("L2CAP - Calling ConnectCfm_Cb(), CID: 0x%04x  Status: %d", p_ccb->local_cid, p_ci->status);
            l2cu_release_ccb (p_ccb);
            (*connect_cfm)(local_cid, p_ci->status);
        }
        break;

    case L2CEVT_L2CA_CONNECT_REQ:                       /* API connect request  */
        /* Cancel sniff mode if needed */
    {
        tBTM_PM_PWR_MD settings;
// btla-specific ++
        memset((void *)&settings, 0, sizeof(settings));
// btla-specific --
        settings.mode = BTM_PM_MD_ACTIVE;
        /* COVERITY
        Event uninit_use_in_call: Using uninitialized value "settings" (field "settings".timeout uninitialized) in call to function "BTM_SetPowerMode" [details]
        Event uninit_use_in_call: Using uninitialized value "settings.max" in call to function "BTM_SetPowerMode" [details]
        Event uninit_use_in_call: Using uninitialized value "settings.min" in call to function "BTM_SetPowerMode"
        // FALSE-POSITIVE error from Coverity test-tool. Please do NOT remove following comment.
        // coverity[uninit_use_in_call] False-positive: setting the mode to BTM_PM_MD_ACTIVE only uses settings.mode the other data members of tBTM_PM_PWR_MD are ignored
        */
        BTM_SetPowerMode (BTM_PM_SET_ONLY_ID, p_ccb->p_lcb->remote_bd_addr, &settings);
    }

        /* If sec access does not result in started SEC_COM or COMP_NEG are already processed */
    if (btm_sec_l2cap_access_req (p_ccb->p_lcb->remote_bd_addr, p_ccb->p_rcb->psm,
                                  p_ccb->p_lcb->handle, TRUE, &l2c_link_sec_comp, p_ccb) == BTM_CMD_STARTED) {
        p_ccb->chnl_state = CST_ORIG_W4_SEC_COMP;
    }
    break;

    case L2CEVT_SEC_COMP:
        p_ccb->chnl_state = CST_W4_L2CAP_CONNECT_RSP;

        /* Wait for the info resp in this state before sending connect req (if needed) */
        if (!p_ccb->p_lcb->w4_info_rsp) {
            /* Need to have at least one compatible channel to continue */
            if (!l2c_fcr_chk_chan_modes(p_ccb)) {
                l2cu_release_ccb (p_ccb);
                (*p_ccb->p_rcb->api.pL2CA_ConnectCfm_Cb)(local_cid, L2CAP_CONN_NO_LINK);
            } else {
                l2cu_send_peer_connect_req (p_ccb);
                btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CONNECT_TOUT);
            }
        }
        break;

    case L2CEVT_SEC_COMP_NEG:                           /* something is really bad with security */
        L2CAP_TRACE_API ("L2CAP - Calling ConnectCfm_Cb(), CID: 0x%04x  Status: %d", p_ccb->local_cid, L2CAP_CONN_TIMEOUT);
        l2cu_release_ccb (p_ccb);
        (*connect_cfm)(local_cid, L2CAP_CONN_SECURITY_BLOCK);
        break;

    case L2CEVT_L2CAP_CONNECT_REQ:                      /* Peer connect request */
        /* stop link timer to avoid race condition between A2MP, Security, and L2CAP */
        btu_stop_timer (&p_ccb->p_lcb->timer_entry);

        /* Cancel sniff mode if needed */
        {
            tBTM_PM_PWR_MD settings;
// btla-specific ++
            memset((void *)&settings, 0, sizeof(settings));
// btla-specific --
            settings.mode = BTM_PM_MD_ACTIVE;
            /* COVERITY
            Event uninit_use_in_call: Using uninitialized value "settings" (field "settings".timeout uninitialized) in call to function "BTM_SetPowerMode" [details]
            Event uninit_use_in_call: Using uninitialized value "settings.max" in call to function "BTM_SetPowerMode" [details]
            Event uninit_use_in_call: Using uninitialized value "settings.min" in call to function "BTM_SetPowerMode"
            // FALSE-POSITIVE error from Coverity test-tool. Please do NOT remove following comment.
            // coverity[uninit_use_in_call] False-positive: setting the mode to BTM_PM_MD_ACTIVE only uses settings.mode the other data members of tBTM_PM_PWR_MD are ignored
            */
            BTM_SetPowerMode (BTM_PM_SET_ONLY_ID, p_ccb->p_lcb->remote_bd_addr, &settings);
        }

        p_ccb->chnl_state = CST_TERM_W4_SEC_COMP;
        if (btm_sec_l2cap_access_req (p_ccb->p_lcb->remote_bd_addr, p_ccb->p_rcb->psm,
                                      p_ccb->p_lcb->handle, FALSE, &l2c_link_sec_comp, p_ccb) == BTM_CMD_STARTED) {
            /* started the security process, tell the peer to set a longer timer */
            l2cu_send_peer_connect_rsp(p_ccb, L2CAP_CONN_PENDING, 0);
        }
        break;

    case L2CEVT_TIMEOUT:
        L2CAP_TRACE_API ("L2CAP - Calling ConnectCfm_Cb(), CID: 0x%04x  Status: %d", p_ccb->local_cid, L2CAP_CONN_TIMEOUT);
        l2cu_release_ccb (p_ccb);
        (*connect_cfm)(local_cid, L2CAP_CONN_TIMEOUT);
        break;

    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
        GKI_freebuf (p_data);
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                 /* Upper wants to disconnect */
        l2cu_release_ccb (p_ccb);
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_orig_w4_sec_comp
**
** Description      This function handles events when the channel is in
**                  CST_ORIG_W4_SEC_COMP state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_orig_w4_sec_comp (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    tL2CA_DISCONNECT_IND_CB *disconnect_ind = p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb;
    tL2CA_CONNECT_CFM_CB    *connect_cfm = p_ccb->p_rcb->api.pL2CA_ConnectCfm_Cb;
    UINT16                  local_cid = p_ccb->local_cid;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: ORIG_W4_SEC_COMP  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: ORIG_W4_SEC_COMP evt: %d", event);
#endif

#if (L2CAP_UCD_INCLUDED == TRUE)
    if ( local_cid == L2CAP_CONNECTIONLESS_CID ) {
        /* check if this event can be processed by UCD */
        if ( l2c_ucd_process_event (p_ccb, event, p_data) ) {
            /* The event is processed by UCD state machine */
            return;
        }
    }
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                   /* Link was disconnected */
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;

    case L2CEVT_SEC_RE_SEND_CMD:                    /* BTM has enough info to proceed */
    case L2CEVT_LP_CONNECT_CFM:                     /* Link came up         */
        btm_sec_l2cap_access_req (p_ccb->p_lcb->remote_bd_addr, p_ccb->p_rcb->psm,
                                  p_ccb->p_lcb->handle, TRUE, &l2c_link_sec_comp, p_ccb);
        break;

    case L2CEVT_SEC_COMP:                            /* Security completed success */
        /* Wait for the info resp in this state before sending connect req (if needed) */
        p_ccb->chnl_state = CST_W4_L2CAP_CONNECT_RSP;
        if (!p_ccb->p_lcb->w4_info_rsp) {
            /* Need to have at least one compatible channel to continue */
            if (!l2c_fcr_chk_chan_modes(p_ccb)) {
                l2cu_release_ccb (p_ccb);
                (*connect_cfm)(local_cid, L2CAP_CONN_NO_LINK);
            } else {
                btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CONNECT_TOUT);
                l2cu_send_peer_connect_req (p_ccb);          /* Start Connection     */
            }
        }
        break;

    case L2CEVT_SEC_COMP_NEG:
        L2CAP_TRACE_API ("L2CAP - Calling ConnectCfm_Cb(), CID: 0x%04x  Status: %d", p_ccb->local_cid, HCI_ERR_AUTH_FAILURE);

        /* If last channel immediately disconnect the ACL for better security.
           Also prevents a race condition between BTM and L2CAP */
        if ( (p_ccb == p_ccb->p_lcb->ccb_queue.p_first_ccb) && (p_ccb == p_ccb->p_lcb->ccb_queue.p_last_ccb) ) {
            p_ccb->p_lcb->idle_timeout = 0;
        }

        l2cu_release_ccb (p_ccb);
        (*connect_cfm)(local_cid, HCI_ERR_AUTH_FAILURE);
        break;

    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
        GKI_freebuf (p_data);
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                 /* Upper wants to disconnect */
        /* Tell security manager to abort */
        btm_sec_abort_access_req (p_ccb->p_lcb->remote_bd_addr);

        l2cu_release_ccb (p_ccb);
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_term_w4_sec_comp
**
** Description      This function handles events when the channel is in
**                  CST_TERM_W4_SEC_COMP state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_term_w4_sec_comp (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: TERM_W4_SEC_COMP  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: TERM_W4_SEC_COMP evt: %d", event);
#endif

#if (L2CAP_UCD_INCLUDED == TRUE)
    if ( p_ccb->local_cid == L2CAP_CONNECTIONLESS_CID ) {
        /* check if this event can be processed by UCD */
        if ( l2c_ucd_process_event (p_ccb, event, p_data) ) {
            /* The event is processed by UCD state machine */
            return;
        }
    }
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
        /* Tell security manager to abort */
        btm_sec_abort_access_req (p_ccb->p_lcb->remote_bd_addr);

        l2cu_release_ccb (p_ccb);
        break;

    case L2CEVT_SEC_COMP:
        p_ccb->chnl_state = CST_W4_L2CA_CONNECT_RSP;

        /* Wait for the info resp in next state before sending connect ind (if needed) */
        if (!p_ccb->p_lcb->w4_info_rsp) {
            /* Don't need to get info from peer or already retrieved so continue */
            btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CONNECT_TOUT);
            L2CAP_TRACE_API ("L2CAP - Calling Connect_Ind_Cb(), CID: 0x%04x", p_ccb->local_cid);

            (*p_ccb->p_rcb->api.pL2CA_ConnectInd_Cb) (p_ccb->p_lcb->remote_bd_addr, p_ccb->local_cid,
                    p_ccb->p_rcb->psm, p_ccb->remote_id);
        } else {
            /*
            ** L2CAP Connect Response will be sent out by 3 sec timer expiration
            ** because Bluesoleil doesn't respond to L2CAP Information Request.
            ** Bluesoleil seems to disconnect ACL link as failure case, because
            ** it takes too long (4~7secs) to get response.
            ** product version : Bluesoleil 2.1.1.0 EDR Release 060123
            ** stack version   : 05.04.11.20060119
            */

            /* Waiting for the info resp, tell the peer to set a longer timer */
            l2cu_send_peer_connect_rsp(p_ccb, L2CAP_CONN_PENDING, 0);
        }
        break;

    case L2CEVT_SEC_COMP_NEG:
        if (((tL2C_CONN_INFO *)p_data)->status == BTM_DELAY_CHECK) {
            /* start a timer - encryption change not received before L2CAP connect req */
            btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_DELAY_CHECK_SM4);
        } else {
            l2cu_send_peer_connect_rsp (p_ccb, L2CAP_CONN_SECURITY_BLOCK, 0);
            l2cu_release_ccb (p_ccb);
        }
        break;

    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
        GKI_freebuf (p_data);
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                 /* Upper wants to disconnect */
        l2cu_release_ccb (p_ccb);
        break;

    case L2CEVT_L2CAP_DISCONNECT_REQ:                  /* Peer disconnected request */
        l2cu_send_peer_disc_rsp (p_ccb->p_lcb, p_ccb->remote_id, p_ccb->local_cid, p_ccb->remote_cid);

        /* Tell security manager to abort */
        btm_sec_abort_access_req (p_ccb->p_lcb->remote_bd_addr);

        l2cu_release_ccb (p_ccb);
        break;

    case L2CEVT_TIMEOUT:
        /* SM4 related. */
        if (!btsnd_hcic_disconnect (p_ccb->p_lcb->handle, HCI_ERR_AUTH_FAILURE)) {
            L2CAP_TRACE_API ("L2CAP - Calling btsnd_hcic_disconnect for handle %i failed", p_ccb->p_lcb->handle);
            btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, 1);
        }
        break;

    case L2CEVT_SEC_RE_SEND_CMD:                    /* BTM has enough info to proceed */
        btm_sec_l2cap_access_req (p_ccb->p_lcb->remote_bd_addr, p_ccb->p_rcb->psm,
                                  p_ccb->p_lcb->handle, FALSE, &l2c_link_sec_comp, p_ccb);
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_w4_l2cap_connect_rsp
**
** Description      This function handles events when the channel is in
**                  CST_W4_L2CAP_CONNECT_RSP state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_w4_l2cap_connect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    tL2C_CONN_INFO          *p_ci = (tL2C_CONN_INFO *)p_data;
    tL2CA_DISCONNECT_IND_CB *disconnect_ind = p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb;
    tL2CA_CONNECT_CFM_CB    *connect_cfm = p_ccb->p_rcb->api.pL2CA_ConnectCfm_Cb;
    UINT16                  local_cid = p_ccb->local_cid;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: W4_L2CAP_CON_RSP  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: W4_L2CAP_CON_RSP evt: %d", event);
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
        /* Send disc indication unless peer to peer race condition AND normal disconnect */
        /* *((UINT8 *)p_data) != HCI_ERR_PEER_USER happens when peer device try to disconnect for normal reason */
        p_ccb->chnl_state = CST_CLOSED;
        if ((p_ccb->flags & CCB_FLAG_NO_RETRY) || !p_data || (*((UINT8 *)p_data) != HCI_ERR_PEER_USER)) {
            L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed",
                             p_ccb->local_cid);
            l2cu_release_ccb (p_ccb);
            (*disconnect_ind)(local_cid, FALSE);
        }
        p_ccb->flags |= CCB_FLAG_NO_RETRY;
        break;

    case L2CEVT_L2CAP_CONNECT_RSP:                  /* Got peer connect confirm */
        p_ccb->remote_cid = p_ci->remote_cid;
        p_ccb->chnl_state = CST_CONFIG;
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);
        L2CAP_TRACE_API ("L2CAP - Calling Connect_Cfm_Cb(), CID: 0x%04x, Success", p_ccb->local_cid);

        (*p_ccb->p_rcb->api.pL2CA_ConnectCfm_Cb)(local_cid, L2CAP_CONN_OK);
        break;

    case L2CEVT_L2CAP_CONNECT_RSP_PND:              /* Got peer connect pending */
        p_ccb->remote_cid = p_ci->remote_cid;
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CONNECT_TOUT_EXT);
        if (p_ccb->p_rcb->api.pL2CA_ConnectPnd_Cb) {
            L2CAP_TRACE_API ("L2CAP - Calling Connect_Pnd_Cb(), CID: 0x%04x", p_ccb->local_cid);
            (*p_ccb->p_rcb->api.pL2CA_ConnectPnd_Cb)(p_ccb->local_cid);
        }
        break;

    case L2CEVT_L2CAP_CONNECT_RSP_NEG:              /* Peer rejected connection */
        L2CAP_TRACE_API ("L2CAP - Calling Connect_Cfm_Cb(), CID: 0x%04x, Failure Code: %d", p_ccb->local_cid, p_ci->l2cap_result);
        l2cu_release_ccb (p_ccb);
        (*connect_cfm)(local_cid, p_ci->l2cap_result);
        break;

    case L2CEVT_TIMEOUT:
        L2CAP_TRACE_API ("L2CAP - Calling Connect_Cfm_Cb(), CID: 0x%04x, Timeout", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*connect_cfm)(local_cid, L2CAP_CONN_TIMEOUT);
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                 /* Upper wants to disconnect */
        /* If we know peer CID from connect pending, we can send disconnect */
        if (p_ccb->remote_cid != 0) {
            l2cu_send_peer_disc_req (p_ccb);
            p_ccb->chnl_state = CST_W4_L2CAP_DISCONNECT_RSP;
            btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_DISCONNECT_TOUT);
        } else {
            l2cu_release_ccb (p_ccb);
        }
        break;

    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
        GKI_freebuf (p_data);
        break;

    case L2CEVT_L2CAP_INFO_RSP:
        /* Need to have at least one compatible channel to continue */
        if (!l2c_fcr_chk_chan_modes(p_ccb)) {
            l2cu_release_ccb (p_ccb);
            (*connect_cfm)(local_cid, L2CAP_CONN_NO_LINK);
        } else {
            /* We have feature info, so now send peer connect request */
            btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CONNECT_TOUT);
            l2cu_send_peer_connect_req (p_ccb);          /* Start Connection     */
        }
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_w4_l2ca_connect_rsp
**
** Description      This function handles events when the channel is in
**                  CST_W4_L2CA_CONNECT_RSP state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_w4_l2ca_connect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    tL2C_CONN_INFO          *p_ci;
    tL2CA_DISCONNECT_IND_CB *disconnect_ind = p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb;
    UINT16                  local_cid = p_ccb->local_cid;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: W4_L2CA_CON_RSP  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: W4_L2CA_CON_RSP evt: %d", event);
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;

    case L2CEVT_L2CA_CONNECT_RSP:
        p_ci = (tL2C_CONN_INFO *)p_data;

        /* Result should be OK or PENDING */
        if ((!p_ci) || (p_ci->l2cap_result == L2CAP_CONN_OK)) {
            l2cu_send_peer_connect_rsp (p_ccb, L2CAP_CONN_OK, 0);
            p_ccb->chnl_state = CST_CONFIG;
            btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);
        } else {
            /* If pending, stay in same state and start extended timer */
            l2cu_send_peer_connect_rsp (p_ccb, p_ci->l2cap_result, p_ci->l2cap_status);
            btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CONNECT_TOUT_EXT);
        }
        break;

    case L2CEVT_L2CA_CONNECT_RSP_NEG:
        p_ci = (tL2C_CONN_INFO *)p_data;
        l2cu_send_peer_connect_rsp (p_ccb, p_ci->l2cap_result, p_ci->l2cap_status);
        l2cu_release_ccb (p_ccb);
        break;

    case L2CEVT_TIMEOUT:
        l2cu_send_peer_connect_rsp (p_ccb, L2CAP_CONN_NO_PSM, 0);
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;

    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
        GKI_freebuf (p_data);
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                 /* Upper wants to disconnect */
        l2cu_send_peer_disc_req (p_ccb);
        p_ccb->chnl_state = CST_W4_L2CAP_DISCONNECT_RSP;
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_DISCONNECT_TOUT);
        break;

    case L2CEVT_L2CAP_INFO_RSP:
        /* We have feature info, so now give the upper layer connect IND */
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CONNECT_TOUT);
        L2CAP_TRACE_API ("L2CAP - Calling Connect_Ind_Cb(), CID: 0x%04x", p_ccb->local_cid);

        (*p_ccb->p_rcb->api.pL2CA_ConnectInd_Cb) (p_ccb->p_lcb->remote_bd_addr,
                p_ccb->local_cid,
                p_ccb->p_rcb->psm,
                p_ccb->remote_id);
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_config
**
** Description      This function handles events when the channel is in
**                  CONFIG state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_config (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    tL2CAP_CFG_INFO         *p_cfg = (tL2CAP_CFG_INFO *)p_data;
    tL2CA_DISCONNECT_IND_CB *disconnect_ind = p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb;
    UINT16                  local_cid = p_ccb->local_cid;
    UINT8                   cfg_result;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: CONFIG  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: CONFIG evt: %d", event);
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;

    case L2CEVT_L2CAP_CONFIG_REQ:                  /* Peer config request   */

        if ((cfg_result = l2cu_process_peer_cfg_req (p_ccb, p_cfg)) == L2CAP_PEER_CFG_OK) {
            L2CAP_TRACE_EVENT ("L2CAP - Calling Config_Req_Cb(), CID: 0x%04x, C-bit %d",
                               p_ccb->local_cid, (p_cfg->flags & L2CAP_CFG_FLAGS_MASK_CONT));
            (*p_ccb->p_rcb->api.pL2CA_ConfigInd_Cb)(p_ccb->local_cid, p_cfg);
        } else if (cfg_result == L2CAP_PEER_CFG_DISCONNECT) {
            /* Disconnect if channels are incompatible */
            L2CAP_TRACE_EVENT ("L2CAP - incompatible configurations disconnect");
            l2cu_disconnect_chnl (p_ccb);
        } else { /* Return error to peer so he can renegotiate if possible */
            L2CAP_TRACE_EVENT ("L2CAP - incompatible configurations trying reconfig");
            l2cu_send_peer_config_rsp (p_ccb, p_cfg);
        }
        break;

    case L2CEVT_L2CAP_CONFIG_RSP:                  /* Peer config response  */
        l2cu_process_peer_cfg_rsp (p_ccb, p_cfg);

        if (p_cfg->result != L2CAP_CFG_PENDING) {
            /* TBD: When config options grow beyong minimum MTU (48 bytes)
             *      logic needs to be added to handle responses with
             *      continuation bit set in flags field.
             *       1. Send additional config request out until C-bit is cleared in response
             */
            p_ccb->config_done |= OB_CFG_DONE;

            if (p_ccb->config_done & IB_CFG_DONE) {
                /* Verify two sides are in compatible modes before continuing */
                if (p_ccb->our_cfg.fcr.mode != p_ccb->peer_cfg.fcr.mode) {
                    l2cu_send_peer_disc_req (p_ccb);
                    L2CAP_TRACE_WARNING ("L2CAP - Calling Disconnect_Ind_Cb(Incompatible CFG), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
                    l2cu_release_ccb (p_ccb);
                    (*disconnect_ind)(local_cid, FALSE);
                    break;
                }

                p_ccb->config_done |= RECONFIG_FLAG;
                p_ccb->chnl_state = CST_OPEN;
                l2c_link_adjust_chnl_allocation ();
                btu_stop_timer (&p_ccb->timer_entry);

                /* If using eRTM and waiting for an ACK, restart the ACK timer */
                if (p_ccb->fcrb.wait_ack) {
                    l2c_fcr_start_timer(p_ccb);
                }

                /*
                ** check p_ccb->our_cfg.fcr.mon_tout and p_ccb->our_cfg.fcr.rtrans_tout
                ** we may set them to zero when sending config request during renegotiation
                */
                if ((p_ccb->our_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE)
                        && ((p_ccb->our_cfg.fcr.mon_tout == 0) || (p_ccb->our_cfg.fcr.rtrans_tout))) {
                    l2c_fcr_adj_monitor_retran_timeout (p_ccb);
                }

#if (L2CAP_ERTM_STATS == TRUE)
                p_ccb->fcrb.connect_tick_count = GKI_get_os_tick_count();
#endif
                /* See if we can forward anything on the hold queue */
                if (!GKI_queue_is_empty(&p_ccb->xmit_hold_q)) {
                    l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, NULL);
                }
            }
        }

        L2CAP_TRACE_API ("L2CAP - Calling Config_Rsp_Cb(), CID: 0x%04x", p_ccb->local_cid);
        (*p_ccb->p_rcb->api.pL2CA_ConfigCfm_Cb)(p_ccb->local_cid, p_cfg);
        break;

    case L2CEVT_L2CAP_CONFIG_RSP_NEG:              /* Peer config error rsp */
        /* Disable the Timer */
        btu_stop_timer (&p_ccb->timer_entry);

        /* If failure was channel mode try to renegotiate */
        if (l2c_fcr_renegotiate_chan(p_ccb, p_cfg) == FALSE) {
            L2CAP_TRACE_API ("L2CAP - Calling Config_Rsp_Cb(), CID: 0x%04x, Failure: %d", p_ccb->local_cid, p_cfg->result);
            (*p_ccb->p_rcb->api.pL2CA_ConfigCfm_Cb)(p_ccb->local_cid, p_cfg);
        }
        break;

    case L2CEVT_L2CAP_DISCONNECT_REQ:                  /* Peer disconnected request */
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_DISCONNECT_TOUT);
        p_ccb->chnl_state = CST_W4_L2CA_DISCONNECT_RSP;
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  Conf Needed", p_ccb->local_cid);
        (*p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb)(p_ccb->local_cid, TRUE);
        break;

    case L2CEVT_L2CA_CONFIG_REQ:                   /* Upper layer config req   */
        l2cu_process_our_cfg_req (p_ccb, p_cfg);
        l2cu_send_peer_config_req (p_ccb, p_cfg);
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);
        break;

    case L2CEVT_L2CA_CONFIG_RSP:                   /* Upper layer config rsp   */
        l2cu_process_our_cfg_rsp (p_ccb, p_cfg);

        /* Not finished if continuation flag is set */
        if ( (p_cfg->flags & L2CAP_CFG_FLAGS_MASK_CONT) || (p_cfg->result == L2CAP_CFG_PENDING) ) {
            /* Send intermediate response; remain in cfg state */
            l2cu_send_peer_config_rsp (p_ccb, p_cfg);
            break;
        }

        /* Local config done; clear cached configuration in case reconfig takes place later */
        p_ccb->peer_cfg.mtu_present = FALSE;
        p_ccb->peer_cfg.flush_to_present = FALSE;
        p_ccb->peer_cfg.qos_present = FALSE;

        p_ccb->config_done |= IB_CFG_DONE;

        if (p_ccb->config_done & OB_CFG_DONE) {
            /* Verify two sides are in compatible modes before continuing */
            if (p_ccb->our_cfg.fcr.mode != p_ccb->peer_cfg.fcr.mode) {
                l2cu_send_peer_disc_req (p_ccb);
                L2CAP_TRACE_WARNING ("L2CAP - Calling Disconnect_Ind_Cb(Incompatible CFG), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
                l2cu_release_ccb (p_ccb);
                (*disconnect_ind)(local_cid, FALSE);
                break;
            }

            p_ccb->config_done |= RECONFIG_FLAG;
            p_ccb->chnl_state = CST_OPEN;
            l2c_link_adjust_chnl_allocation ();
            btu_stop_timer (&p_ccb->timer_entry);
        }

        l2cu_send_peer_config_rsp (p_ccb, p_cfg);

        /* If using eRTM and waiting for an ACK, restart the ACK timer */
        if (p_ccb->fcrb.wait_ack) {
            l2c_fcr_start_timer(p_ccb);
        }

#if (L2CAP_ERTM_STATS == TRUE)
        p_ccb->fcrb.connect_tick_count = GKI_get_os_tick_count();
#endif

        /* See if we can forward anything on the hold queue */
        if ( (p_ccb->chnl_state == CST_OPEN) && (!GKI_queue_is_empty(&p_ccb->xmit_hold_q))) {
            l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, NULL);
        }
        break;

    case L2CEVT_L2CA_CONFIG_RSP_NEG:               /* Upper layer config reject */
        l2cu_send_peer_config_rsp (p_ccb, p_cfg);
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                 /* Upper wants to disconnect */
        l2cu_send_peer_disc_req (p_ccb);
        p_ccb->chnl_state = CST_W4_L2CAP_DISCONNECT_RSP;
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_DISCONNECT_TOUT);
        break;

    case L2CEVT_L2CAP_DATA:                        /* Peer data packet rcvd    */
        L2CAP_TRACE_API ("L2CAP - Calling DataInd_Cb(), CID: 0x%04x", p_ccb->local_cid);
#if (L2CAP_NUM_FIXED_CHNLS > 0)
        if (p_ccb->local_cid >= L2CAP_FIRST_FIXED_CHNL &&
                p_ccb->local_cid <= L2CAP_LAST_FIXED_CHNL) {
            if (p_ccb->local_cid < L2CAP_BASE_APPL_CID) {
                if (l2cb.fixed_reg[p_ccb->local_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)
                    (*l2cb.fixed_reg[p_ccb->local_cid - L2CAP_FIRST_FIXED_CHNL].pL2CA_FixedData_Cb)
                    (p_ccb->local_cid, p_ccb->p_lcb->remote_bd_addr, (BT_HDR *)p_data);
                else {
                    GKI_freebuf (p_data);
                }
                break;
            }
        }
#endif
        (*p_ccb->p_rcb->api.pL2CA_DataInd_Cb)(p_ccb->local_cid, (BT_HDR *)p_data);
        break;

    case L2CEVT_L2CA_DATA_WRITE:                   /* Upper layer data to send */
        if (p_ccb->config_done & OB_CFG_DONE) {
            l2c_enqueue_peer_data (p_ccb, (BT_HDR *)p_data);
        } else {
            GKI_freebuf (p_data);
        }
        break;

    case L2CEVT_TIMEOUT:
        l2cu_send_peer_disc_req (p_ccb);
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed",
                         p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_open
**
** Description      This function handles events when the channel is in
**                  OPEN state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_open (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    UINT16                  local_cid = p_ccb->local_cid;
    tL2CAP_CFG_INFO         *p_cfg;
    tL2C_CHNL_STATE         tempstate;
    UINT8                   tempcfgdone;
    UINT8                   cfg_result;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: OPEN  evt: %s",
                       p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: OPEN evt: %d", event);
#endif

#if (L2CAP_UCD_INCLUDED == TRUE)
    if ( local_cid == L2CAP_CONNECTIONLESS_CID ) {
        /* check if this event can be processed by UCD */
        if ( l2c_ucd_process_event (p_ccb, event, p_data) ) {
            /* The event is processed by UCD state machine */
            return;
        }
    }
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed",
                         p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        if (p_ccb->p_rcb) {
            (*p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb)(local_cid, FALSE);
        }
        break;

    case L2CEVT_LP_QOS_VIOLATION_IND:               /* QOS violation         */
        /* Tell upper layer. If service guaranteed, then clear the channel   */
        if (p_ccb->p_rcb->api.pL2CA_QoSViolationInd_Cb) {
            (*p_ccb->p_rcb->api.pL2CA_QoSViolationInd_Cb)(p_ccb->p_lcb->remote_bd_addr);
        }
        break;

    case L2CEVT_L2CAP_CONFIG_REQ:                  /* Peer config request   */
        p_cfg = (tL2CAP_CFG_INFO *)p_data;

        tempstate = p_ccb->chnl_state;
        tempcfgdone = p_ccb->config_done;
        p_ccb->chnl_state = CST_CONFIG;
        p_ccb->config_done &= ~CFG_DONE_MASK;

        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);

        if ((cfg_result = l2cu_process_peer_cfg_req (p_ccb, p_cfg)) == L2CAP_PEER_CFG_OK) {
            (*p_ccb->p_rcb->api.pL2CA_ConfigInd_Cb)(p_ccb->local_cid, p_cfg);
        }

        /* Error in config parameters: reset state and config flag */
        else if (cfg_result == L2CAP_PEER_CFG_UNACCEPTABLE) {
            btu_stop_timer(&p_ccb->timer_entry);
            p_ccb->chnl_state = tempstate;
            p_ccb->config_done = tempcfgdone;
            l2cu_send_peer_config_rsp (p_ccb, p_cfg);
        } else { /* L2CAP_PEER_CFG_DISCONNECT */
            /* Disconnect if channels are incompatible
             * Note this should not occur if reconfigure
             * since this should have never passed original config.
             */
            l2cu_disconnect_chnl (p_ccb);
        }
        break;

    case L2CEVT_L2CAP_DISCONNECT_REQ:                  /* Peer disconnected request */
// btla-specific ++
        /* Make sure we are not in sniff mode */
    {
        tBTM_PM_PWR_MD settings;
        memset((void *)&settings, 0, sizeof(settings));
        settings.mode = BTM_PM_MD_ACTIVE;
        BTM_SetPowerMode (BTM_PM_SET_ONLY_ID, p_ccb->p_lcb->remote_bd_addr, &settings);
    }
// btla-specific --

    p_ccb->chnl_state = CST_W4_L2CA_DISCONNECT_RSP;
    btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_DISCONNECT_TOUT);
    L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  Conf Needed", p_ccb->local_cid);
    (*p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb)(p_ccb->local_cid, TRUE);
    break;

    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
        if ((p_ccb->p_rcb) && (p_ccb->p_rcb->api.pL2CA_DataInd_Cb)) {
            (*p_ccb->p_rcb->api.pL2CA_DataInd_Cb)(p_ccb->local_cid, (BT_HDR *)p_data);
        }
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                 /* Upper wants to disconnect */
        /* Make sure we are not in sniff mode */
    {
        tBTM_PM_PWR_MD settings;
        memset((void *)&settings, 0, sizeof(settings));
        settings.mode = BTM_PM_MD_ACTIVE;
        BTM_SetPowerMode (BTM_PM_SET_ONLY_ID, p_ccb->p_lcb->remote_bd_addr, &settings);
    }

    l2cu_send_peer_disc_req (p_ccb);
    p_ccb->chnl_state = CST_W4_L2CAP_DISCONNECT_RSP;
    btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_DISCONNECT_TOUT);
    break;

    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
        l2c_enqueue_peer_data (p_ccb, (BT_HDR *)p_data);
        l2c_link_check_send_pkts (p_ccb->p_lcb, NULL, NULL);
        break;

    case L2CEVT_L2CA_CONFIG_REQ:                   /* Upper layer config req   */
        p_ccb->chnl_state = CST_CONFIG;
        p_ccb->config_done &= ~CFG_DONE_MASK;
        l2cu_process_our_cfg_req (p_ccb, (tL2CAP_CFG_INFO *)p_data);
        l2cu_send_peer_config_req (p_ccb, (tL2CAP_CFG_INFO *)p_data);
        btu_start_timer (&p_ccb->timer_entry, BTU_TTYPE_L2CAP_CHNL, L2CAP_CHNL_CFG_TIMEOUT);
        break;

    case L2CEVT_TIMEOUT:
        /* Process the monitor/retransmission time-outs in flow control/retrans mode */
        if (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_ERTM_MODE) {
            l2c_fcr_proc_tout (p_ccb);
        }
        break;

    case L2CEVT_ACK_TIMEOUT:
        l2c_fcr_proc_ack_tout (p_ccb);
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_w4_l2cap_disconnect_rsp
**
** Description      This function handles events when the channel is in
**                  CST_W4_L2CAP_DISCONNECT_RSP state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_w4_l2cap_disconnect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    tL2CA_DISCONNECT_CFM_CB *disconnect_cfm = p_ccb->p_rcb->api.pL2CA_DisconnectCfm_Cb;
    UINT16                  local_cid = p_ccb->local_cid;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: W4_L2CAP_DISC_RSP  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: W4_L2CAP_DISC_RSP evt: %d", event);
#endif

    switch (event) {
    case L2CEVT_L2CAP_DISCONNECT_RSP:                /* Peer disconnect response */
        l2cu_release_ccb (p_ccb);
        if (disconnect_cfm) {
            L2CAP_TRACE_API ("L2CAP - Calling DisconnectCfm_Cb(), CID: 0x%04x", local_cid);
            (*disconnect_cfm)(local_cid, L2CAP_DISC_OK);
        }
        break;

    case L2CEVT_L2CAP_DISCONNECT_REQ:                /* Peer disconnect request  */
        l2cu_send_peer_disc_rsp (p_ccb->p_lcb, p_ccb->remote_id, p_ccb->local_cid, p_ccb->remote_cid);
        l2cu_release_ccb (p_ccb);
        if (disconnect_cfm) {
            L2CAP_TRACE_API ("L2CAP - Calling DisconnectCfm_Cb(), CID: 0x%04x", local_cid);
            (*disconnect_cfm)(local_cid, L2CAP_DISC_OK);
        }
        break;

    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
    case L2CEVT_TIMEOUT:                            /* Timeout */
        l2cu_release_ccb (p_ccb);
        if (disconnect_cfm) {
            L2CAP_TRACE_API ("L2CAP - Calling DisconnectCfm_Cb(), CID: 0x%04x", local_cid);
            (*disconnect_cfm)(local_cid, L2CAP_DISC_TIMEOUT);
        }
        break;

    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
        GKI_freebuf (p_data);
        break;
    }
}


/*******************************************************************************
**
** Function         l2c_csm_w4_l2ca_disconnect_rsp
**
** Description      This function handles events when the channel is in
**                  CST_W4_L2CA_DISCONNECT_RSP state.
**
** Returns          void
**
*******************************************************************************/
static void l2c_csm_w4_l2ca_disconnect_rsp (tL2C_CCB *p_ccb, UINT16 event, void *p_data)
{
    tL2CA_DISCONNECT_IND_CB *disconnect_ind = p_ccb->p_rcb->api.pL2CA_DisconnectInd_Cb;
    UINT16                  local_cid = p_ccb->local_cid;

#if (BT_TRACE_VERBOSE == TRUE)
    L2CAP_TRACE_EVENT ("L2CAP - LCID: 0x%04x  st: W4_L2CA_DISC_RSP  evt: %s", p_ccb->local_cid, l2c_csm_get_event_name (event));
#else
    L2CAP_TRACE_EVENT ("L2CAP - st: W4_L2CA_DISC_RSP evt: %d", event);
#endif

    switch (event) {
    case L2CEVT_LP_DISCONNECT_IND:                  /* Link was disconnected */
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;

    case L2CEVT_TIMEOUT:
        l2cu_send_peer_disc_rsp (p_ccb->p_lcb, p_ccb->remote_id, p_ccb->local_cid, p_ccb->remote_cid);
        L2CAP_TRACE_API ("L2CAP - Calling Disconnect_Ind_Cb(), CID: 0x%04x  No Conf Needed", p_ccb->local_cid);
        l2cu_release_ccb (p_ccb);
        (*disconnect_ind)(local_cid, FALSE);
        break;

    case L2CEVT_L2CA_DISCONNECT_REQ:                /* Upper disconnect request */
    case L2CEVT_L2CA_DISCONNECT_RSP:                /* Upper disconnect response */
        l2cu_send_peer_disc_rsp (p_ccb->p_lcb, p_ccb->remote_id, p_ccb->local_cid, p_ccb->remote_cid);
        l2cu_release_ccb (p_ccb);
        break;

    case L2CEVT_L2CAP_DATA:                         /* Peer data packet rcvd    */
    case L2CEVT_L2CA_DATA_WRITE:                    /* Upper layer data to send */
        GKI_freebuf (p_data);
        break;
    }
}


#if (BT_TRACE_VERBOSE == TRUE)
/*******************************************************************************
**
** Function         l2c_csm_get_event_name
**
** Description      This function returns the event name.
**
** NOTE             conditionally compiled to save memory.
**
** Returns          pointer to the name
**
*******************************************************************************/
static char *l2c_csm_get_event_name (UINT16 event)
{
    switch (event) {
    case L2CEVT_LP_CONNECT_CFM:                  /* Lower layer connect confirm          */
        return ("LOWER_LAYER_CONNECT_CFM");
    case L2CEVT_LP_CONNECT_CFM_NEG:              /* Lower layer connect confirm (failed) */
        return ("LOWER_LAYER_CONNECT_CFM_NEG");
    case L2CEVT_LP_CONNECT_IND:                  /* Lower layer connect indication       */
        return ("LOWER_LAYER_CONNECT_IND");
    case L2CEVT_LP_DISCONNECT_IND:               /* Lower layer disconnect indication    */
        return ("LOWER_LAYER_DISCONNECT_IND");
    case L2CEVT_LP_QOS_CFM:                      /* Lower layer QOS confirmation         */
        return ("LOWER_LAYER_QOS_CFM");
    case L2CEVT_LP_QOS_CFM_NEG:                  /* Lower layer QOS confirmation (failed)*/
        return ("LOWER_LAYER_QOS_CFM_NEG");
    case L2CEVT_LP_QOS_VIOLATION_IND:            /* Lower layer QOS violation indication */
        return ("LOWER_LAYER_QOS_VIOLATION_IND");

    case L2CEVT_SEC_COMP:                        /* Security cleared successfully        */
        return ("SECURITY_COMPLETE");
    case L2CEVT_SEC_COMP_NEG:                    /* Security procedure failed            */
        return ("SECURITY_COMPLETE_NEG");

    case L2CEVT_L2CAP_CONNECT_REQ:               /* Peer connection request              */
        return ("PEER_CONNECT_REQ");
    case L2CEVT_L2CAP_CONNECT_RSP:               /* Peer connection response             */
        return ("PEER_CONNECT_RSP");
    case L2CEVT_L2CAP_CONNECT_RSP_PND:           /* Peer connection response pending     */
        return ("PEER_CONNECT_RSP_PND");
    case L2CEVT_L2CAP_CONNECT_RSP_NEG:           /* Peer connection response (failed)    */
        return ("PEER_CONNECT_RSP_NEG");
    case L2CEVT_L2CAP_CONFIG_REQ:                /* Peer configuration request           */
        return ("PEER_CONFIG_REQ");
    case L2CEVT_L2CAP_CONFIG_RSP:                /* Peer configuration response          */
        return ("PEER_CONFIG_RSP");
    case L2CEVT_L2CAP_CONFIG_RSP_NEG:            /* Peer configuration response (failed) */
        return ("PEER_CONFIG_RSP_NEG");
    case L2CEVT_L2CAP_DISCONNECT_REQ:            /* Peer disconnect request              */
        return ("PEER_DISCONNECT_REQ");
    case L2CEVT_L2CAP_DISCONNECT_RSP:            /* Peer disconnect response             */
        return ("PEER_DISCONNECT_RSP");
    case L2CEVT_L2CAP_DATA:                      /* Peer data                            */
        return ("PEER_DATA");

    case L2CEVT_L2CA_CONNECT_REQ:                /* Upper layer connect request          */
        return ("UPPER_LAYER_CONNECT_REQ");
    case L2CEVT_L2CA_CONNECT_RSP:                /* Upper layer connect response         */
        return ("UPPER_LAYER_CONNECT_RSP");
    case L2CEVT_L2CA_CONNECT_RSP_NEG:            /* Upper layer connect response (failed)*/
        return ("UPPER_LAYER_CONNECT_RSP_NEG");
    case L2CEVT_L2CA_CONFIG_REQ:                 /* Upper layer config request           */
        return ("UPPER_LAYER_CONFIG_REQ");
    case L2CEVT_L2CA_CONFIG_RSP:                 /* Upper layer config response          */
        return ("UPPER_LAYER_CONFIG_RSP");
    case L2CEVT_L2CA_CONFIG_RSP_NEG:             /* Upper layer config response (failed) */
        return ("UPPER_LAYER_CONFIG_RSP_NEG");
    case L2CEVT_L2CA_DISCONNECT_REQ:             /* Upper layer disconnect request       */
        return ("UPPER_LAYER_DISCONNECT_REQ");
    case L2CEVT_L2CA_DISCONNECT_RSP:             /* Upper layer disconnect response      */
        return ("UPPER_LAYER_DISCONNECT_RSP");
    case L2CEVT_L2CA_DATA_READ:                  /* Upper layer data read                */
        return ("UPPER_LAYER_DATA_READ");
    case L2CEVT_L2CA_DATA_WRITE:                 /* Upper layer data write               */
        return ("UPPER_LAYER_DATA_WRITE");
    case L2CEVT_TIMEOUT:                         /* Timeout                              */
        return ("TIMEOUT");
    case L2CEVT_SEC_RE_SEND_CMD:
        return ("SEC_RE_SEND_CMD");
    case L2CEVT_L2CAP_INFO_RSP:                  /* Peer information response            */
        return ("L2CEVT_L2CAP_INFO_RSP");
    case L2CEVT_ACK_TIMEOUT:
        return ("L2CEVT_ACK_TIMEOUT");

    default:
        return ("???? UNKNOWN EVENT");
    }
}
#endif /* (BT_TRACE_VERBOSE == TRUE) */


/*******************************************************************************
**
** Function         l2c_enqueue_peer_data
**
** Description      Enqueues data destined for the peer in the ccb. Handles
**                  FCR segmentation and checks for congestion.
**
** Returns          void
**
*******************************************************************************/
void l2c_enqueue_peer_data (tL2C_CCB *p_ccb, BT_HDR *p_buf)
{
    UINT8       *p;

    if (p_ccb->peer_cfg.fcr.mode != L2CAP_FCR_BASIC_MODE) {
        p_buf->event = 0;
    } else {
        /* Save the channel ID for faster counting */
        p_buf->event = p_ccb->local_cid;

        /* Step back to add the L2CAP header */
        p_buf->offset -= L2CAP_PKT_OVERHEAD;
        p_buf->len    += L2CAP_PKT_OVERHEAD;

        /* Set the pointer to the beginning of the data */
        p = (UINT8 *)(p_buf + 1) + p_buf->offset;

        /* Now the L2CAP header */
        UINT16_TO_STREAM (p, p_buf->len - L2CAP_PKT_OVERHEAD);
        UINT16_TO_STREAM (p, p_ccb->remote_cid);
    }

    GKI_enqueue (&p_ccb->xmit_hold_q, p_buf);

    l2cu_check_channel_congestion (p_ccb);

#if (L2CAP_ROUND_ROBIN_CHANNEL_SERVICE == TRUE)
    /* if new packet is higher priority than serving ccb and it is not overrun */
    if (( p_ccb->p_lcb->rr_pri > p_ccb->ccb_priority )
            && ( p_ccb->p_lcb->rr_serv[p_ccb->ccb_priority].quota > 0)) {
        /* send out higher priority packet */
        p_ccb->p_lcb->rr_pri = p_ccb->ccb_priority;
    }
#endif

    /* if we are doing a round robin scheduling, set the flag */
    if (p_ccb->p_lcb->link_xmit_quota == 0) {
        l2cb.check_round_robin = TRUE;
    }
}