path: root/stack/btm/btm_pm.c

/******************************************************************************
 *
 *  Copyright (C) 2000-2012 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 functions that manages ACL link modes.
 *  This includes operations such as active, hold,
 *  park and sniff modes.
 *
 *  This module contains both internal and external (API)
 *  functions. External (API) functions are distinguishable
 *  by their names beginning with uppercase BTM.
 *
 *****************************************************************************/

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stddef.h>
#include "bt_types.h"
#include "gki.h"
#include "hcimsgs.h"
#include "btu.h"
#include "btm_api.h"
#include "btm_int.h"
#include "l2c_int.h"
#include "hcidefs.h"


#if BTM_PWR_MGR_INCLUDED == TRUE

/* This compile option is only useful when the FW has a bug
 * it automatically uses single slot when entering SNIFF mode, but does not restore the setting
 * This issue was found when A2DP link goes into sniff and existing sniff still has choppy audio.
 * If this issue is seen, look for FW solution first.
 * This work around code will be removed later. */
#ifndef BTM_PM_SNIFF_SLOT_WORK_AROUND
#define BTM_PM_SNIFF_SLOT_WORK_AROUND       FALSE
#endif

/*****************************************************************************/
/*      to handle different modes                                            */
/*****************************************************************************/
#define BTM_PM_STORED_MASK      0x80 /* set this mask if the command is stored */
#define BTM_PM_NUM_SET_MODES    3 /* only hold, sniff & park */

/* Usage:  (ptr_features[ offset ] & mask )?TRUE:FALSE */
/* offset to supported feature */
const UINT8 btm_pm_mode_off[BTM_PM_NUM_SET_MODES] = {0,    0,    1};
/* mask to supported feature */
const UINT8 btm_pm_mode_msk[BTM_PM_NUM_SET_MODES] = {0x40, 0x80, 0x01};

#define BTM_PM_GET_MD1      1
#define BTM_PM_GET_MD2      2
#define BTM_PM_GET_COMP     3

const UINT8 btm_pm_md_comp_matrix[BTM_PM_NUM_SET_MODES*BTM_PM_NUM_SET_MODES] =
{
    BTM_PM_GET_COMP,
    BTM_PM_GET_MD2,
    BTM_PM_GET_MD2,

    BTM_PM_GET_MD1,
    BTM_PM_GET_COMP,
    BTM_PM_GET_MD1,

    BTM_PM_GET_MD1,
    BTM_PM_GET_MD2,
    BTM_PM_GET_COMP
};

/* function prototype */
static int btm_pm_find_acl_ind(BD_ADDR remote_bda);
static tBTM_STATUS btm_pm_snd_md_req( UINT8 pm_id, int link_ind, tBTM_PM_PWR_MD *p_mode );

/*
#ifdef BTM_PM_DEBUG
#undef BTM_PM_DEBUG
#define BTM_PM_DEBUG    TRUE
#endif
*/

#if BTM_PM_DEBUG == TRUE
const char * btm_pm_state_str[] =
{
    "pm_active_state",
    "pm_hold_state",
    "pm_sniff_state",
    "pm_park_state",
    "pm_pend_state"
};

const char * btm_pm_event_str[] =
{
    "pm_set_mode_event",
    "pm_hci_sts_event",
    "pm_mod_chg_event",
    "pm_update_event"
};

const char * btm_pm_action_str[] =
{
    "pm_set_mode_action",
    "pm_update_db_action",
    "pm_mod_chg_action",
    "pm_hci_sts_action",
    "pm_update_action"
};
#endif

/*****************************************************************************/
/*                     P U B L I C  F U N C T I O N S                        */
/*****************************************************************************/
/*******************************************************************************
**
** Function         BTM_PmRegister
**
** Description      register or deregister with power manager
**
** Returns          BTM_SUCCESS if successful,
**                  BTM_NO_RESOURCES if no room to hold registration
**                  BTM_ILLEGAL_VALUE
**
*******************************************************************************/
tBTM_STATUS BTM_PmRegister (UINT8 mask, UINT8 *p_pm_id, tBTM_PM_STATUS_CBACK *p_cb)
{
    int xx;

    /* de-register */
    if(mask & BTM_PM_DEREG)
    {
        if(*p_pm_id >= BTM_MAX_PM_RECORDS)
            return BTM_ILLEGAL_VALUE;
        btm_cb.pm_reg_db[*p_pm_id].mask = BTM_PM_REC_NOT_USED;
        return BTM_SUCCESS;
    }

    for(xx=0; xx<BTM_MAX_PM_RECORDS; xx++)
    {
        /* find an unused entry */
        if(btm_cb.pm_reg_db[xx].mask == BTM_PM_REC_NOT_USED)
        {
            /* if register for notification, should provide callback routine */
            if(mask & BTM_PM_REG_NOTIF)
            {
                if(p_cb == NULL)
                    return BTM_ILLEGAL_VALUE;
                btm_cb.pm_reg_db[xx].cback = p_cb;
            }
            btm_cb.pm_reg_db[xx].mask = mask;
            *p_pm_id = xx;
            return BTM_SUCCESS;
        }
    }

    return BTM_NO_RESOURCES;
}

/*******************************************************************************
**
** Function         BTM_SetPowerMode
**
** Description      store the mode in control block or
**                  alter ACL connection behavior.
**
** Returns          BTM_SUCCESS if successful,
**                  BTM_UNKNOWN_ADDR if bd addr is not active or bad
**
*******************************************************************************/
tBTM_STATUS BTM_SetPowerMode (UINT8 pm_id, BD_ADDR remote_bda, tBTM_PM_PWR_MD *p_mode)
{
    UINT8               *p_features;
    int               ind, acl_ind;
    tBTM_PM_MCB *p_cb = NULL;   /* per ACL link */
    tBTM_PM_MODE        mode;
    int                 temp_pm_id;


    if(pm_id >= BTM_MAX_PM_RECORDS)
        pm_id = BTM_PM_SET_ONLY_ID;

    if(p_mode == NULL)
        return BTM_ILLEGAL_VALUE;

    BTM_TRACE_API3( "BTM_SetPowerMode: pm_id %d BDA: %08x mode:0x%x", pm_id,
                   (remote_bda[2]<<24)+(remote_bda[3]<<16)+(remote_bda[4]<<8)+remote_bda[5], p_mode->mode);

    /* take out the force bit */
    mode = p_mode->mode & ~BTM_PM_MD_FORCE;

    acl_ind = btm_pm_find_acl_ind(remote_bda);
    if(acl_ind == MAX_L2CAP_LINKS)
        return (BTM_UNKNOWN_ADDR);

    p_cb = &(btm_cb.pm_mode_db[acl_ind]);

    if(mode != BTM_PM_MD_ACTIVE)
    {
        /* check if the requested mode is supported */
        ind = mode - BTM_PM_MD_HOLD; /* make it base 0 */
        p_features = BTM_ReadLocalFeatures();
        if( !(p_features[ btm_pm_mode_off[ind] ] & btm_pm_mode_msk[ind] ) )
            return BTM_MODE_UNSUPPORTED;
    }

    if(mode == p_cb->state) /* the requested mode is current mode */
    {
        /* already in the requested mode and the current interval has less latency than the max */
        if( (mode == BTM_PM_MD_ACTIVE) ||
            ((p_mode->mode & BTM_PM_MD_FORCE) && (p_mode->max >= p_cb->interval) && (p_mode->min <= p_cb->interval)) ||
            ((p_mode->mode & BTM_PM_MD_FORCE)==0 && (p_mode->max >= p_cb->interval)) )
        {
            BTM_TRACE_DEBUG4( "BTM_SetPowerMode: mode:0x%x interval %d max:%d, min:%d", p_mode->mode, p_cb->interval, p_mode->max, p_mode->min);
            return BTM_SUCCESS;
        }
    }

    temp_pm_id = pm_id;
    if(pm_id == BTM_PM_SET_ONLY_ID)
        temp_pm_id = BTM_MAX_PM_RECORDS;

    /* update mode database */
    if( ((pm_id != BTM_PM_SET_ONLY_ID) &&
         (btm_cb.pm_reg_db[pm_id].mask & BTM_PM_REG_SET))
       || ((pm_id == BTM_PM_SET_ONLY_ID) && (btm_cb.pm_pend_link != MAX_L2CAP_LINKS)) )
    {
#if BTM_PM_DEBUG == TRUE
    BTM_TRACE_DEBUG2( "BTM_SetPowerMode: Saving cmd acl_ind %d temp_pm_id %d", acl_ind,temp_pm_id);
#endif
        /* Make sure mask is set to BTM_PM_REG_SET */
        btm_cb.pm_reg_db[temp_pm_id].mask |= BTM_PM_REG_SET;
        *(&p_cb->req_mode[temp_pm_id]) = *((tBTM_PM_PWR_MD *)p_mode);
        p_cb->chg_ind = TRUE;
    }

#if BTM_PM_DEBUG == TRUE
    BTM_TRACE_DEBUG2( "btm_pm state:0x%x, pm_pend_link: %d", p_cb->state, btm_cb.pm_pend_link);
#endif
    /* if mode == hold or pending, return */
    if( (p_cb->state == BTM_PM_STS_HOLD) ||
        (p_cb->state ==  BTM_PM_STS_PENDING) ||
        (btm_cb.pm_pend_link != MAX_L2CAP_LINKS) ) /* command pending */
    {
        if(acl_ind != btm_cb.pm_pend_link)
        {
            /* set the stored mask */
            p_cb->state |= BTM_PM_STORED_MASK;
            BTM_TRACE_DEBUG1( "btm_pm state stored:%d",acl_ind);
        }
        return BTM_CMD_STORED;
    }



    return btm_pm_snd_md_req(pm_id, acl_ind, p_mode);
}

/*******************************************************************************
**
** Function         BTM_ReadPowerMode
**
** Description      This returns the current mode for a specific
**                  ACL connection.
**
** Input Param      remote_bda - device address of desired ACL connection
**
** Output Param     p_mode - address where the current mode is copied into.
**                          BTM_ACL_MODE_NORMAL
**                          BTM_ACL_MODE_HOLD
**                          BTM_ACL_MODE_SNIFF
**                          BTM_ACL_MODE_PARK
**                          (valid only if return code is BTM_SUCCESS)
**
** Returns          BTM_SUCCESS if successful,
**                  BTM_UNKNOWN_ADDR if bd addr is not active or bad
**
*******************************************************************************/
tBTM_STATUS BTM_ReadPowerMode (BD_ADDR remote_bda, tBTM_PM_MODE *p_mode)
{
    int acl_ind;

    if( (acl_ind = btm_pm_find_acl_ind(remote_bda)) == MAX_L2CAP_LINKS)
        return (BTM_UNKNOWN_ADDR);

    *p_mode = btm_cb.pm_mode_db[acl_ind].state;
    return BTM_SUCCESS;
}

/*******************************************************************************
**
** Function         BTM_SetSsrParams
**
** Description      This sends the given SSR parameters for the given ACL
**                  connection if it is in ACTIVE mode.
**
** Input Param      remote_bda - device address of desired ACL connection
**                  max_lat    - maximum latency (in 0.625ms)(0-0xFFFE)
**                  min_rmt_to - minimum remote timeout
**                  min_loc_to - minimum local timeout
**
**
** Returns          BTM_SUCCESS if the HCI command is issued successful,
**                  BTM_UNKNOWN_ADDR if bd addr is not active or bad
**                  BTM_CMD_STORED if the command is stored
**
*******************************************************************************/
tBTM_STATUS BTM_SetSsrParams (BD_ADDR remote_bda, UINT16 max_lat,
                              UINT16 min_rmt_to, UINT16 min_loc_to)
{
#if (BTM_SSR_INCLUDED == TRUE)
    int acl_ind;
    tBTM_PM_MCB *p_cb;

    if( (acl_ind = btm_pm_find_acl_ind(remote_bda)) == MAX_L2CAP_LINKS)
        return (BTM_UNKNOWN_ADDR);

    if(BTM_PM_STS_ACTIVE == btm_cb.pm_mode_db[acl_ind].state ||
        BTM_PM_STS_SNIFF == btm_cb.pm_mode_db[acl_ind].state)
    {
        if (btsnd_hcic_sniff_sub_rate(btm_cb.acl_db[acl_ind].hci_handle, max_lat,
                                      min_rmt_to, min_loc_to))
            return BTM_SUCCESS;
        else
            return BTM_NO_RESOURCES;
    }
    p_cb = &btm_cb.pm_mode_db[acl_ind];
    p_cb->max_lat       = max_lat;
    p_cb->min_rmt_to    = min_rmt_to;
    p_cb->min_loc_to    = min_loc_to;
    return BTM_CMD_STORED;
#else
    return BTM_ILLEGAL_ACTION;
#endif
}

/*******************************************************************************
**
** Function         btm_pm_reset
**
** Description      as a part of the BTM reset process.
**
** Returns          void
**
*******************************************************************************/
void btm_pm_reset(void)
{
    int xx;
    tBTM_PM_STATUS_CBACK *cb = NULL;

    /* clear the pending request for application */
    if( (btm_cb.pm_pend_id != BTM_PM_SET_ONLY_ID) &&
        (btm_cb.pm_reg_db[btm_cb.pm_pend_id].mask & BTM_PM_REG_NOTIF) )
    {
        cb = btm_cb.pm_reg_db[btm_cb.pm_pend_id].cback;
    }

    /* no command pending */
    btm_cb.pm_pend_link = MAX_L2CAP_LINKS;

    /* clear the register record */
    for(xx=0; xx<BTM_MAX_PM_RECORDS; xx++)
    {
        btm_cb.pm_reg_db[xx].mask = BTM_PM_REC_NOT_USED;
    }

    if(cb != NULL)
        (*cb)(btm_cb.acl_db[btm_cb.pm_pend_link].remote_addr, BTM_PM_STS_ERROR, BTM_DEV_RESET, 0);
}

/*******************************************************************************
**
** Function         btm_pm_sm_alloc
**
** Description      This function initializes the control block of an ACL link.
**                  It is called when an ACL connection is created.
**
** Returns          void
**
*******************************************************************************/
void btm_pm_sm_alloc(UINT8 ind)
{
    tBTM_PM_MCB *p_db = &btm_cb.pm_mode_db[ind];   /* per ACL link */
    memset (p_db, 0, sizeof(tBTM_PM_MCB));
    p_db->state = BTM_PM_ST_ACTIVE;
#if BTM_PM_DEBUG == TRUE
    BTM_TRACE_DEBUG2( "btm_pm_sm_alloc ind:%d st:%d", ind, p_db->state);
#endif
}

/*******************************************************************************
**
** Function         btm_pm_find_acl_ind
**
** Description      This function initializes the control block of an ACL link.
**                  It is called when an ACL connection is created.
**
** Returns          void
**
*******************************************************************************/
static int btm_pm_find_acl_ind(BD_ADDR remote_bda)
{
    tACL_CONN   *p = &btm_cb.acl_db[0];
    UINT8 xx;

    for (xx = 0; xx < MAX_L2CAP_LINKS; xx++, p++)
    {
        if ((p->in_use) && (!memcmp (p->remote_addr, remote_bda, BD_ADDR_LEN)))
        {
#if BTM_PM_DEBUG == TRUE
            BTM_TRACE_DEBUG2( "btm_pm_find_acl_ind ind:%d, st:%d", xx, btm_cb.pm_mode_db[xx].state);
#endif
            break;
        }
    }
    return xx;
}

/*******************************************************************************
**
** Function     btm_pm_compare_modes
** Description  get the "more active" mode of the 2
** Returns      void
**
*******************************************************************************/
static tBTM_PM_PWR_MD * btm_pm_compare_modes(tBTM_PM_PWR_MD *p_md1, tBTM_PM_PWR_MD *p_md2, tBTM_PM_PWR_MD *p_res)
{
    UINT8 res;

    if(p_md1 == NULL)
    {
        *p_res = *p_md2;
        p_res->mode &= ~BTM_PM_MD_FORCE;

        return p_md2;
    }

    if(p_md2->mode == BTM_PM_MD_ACTIVE || p_md1->mode == BTM_PM_MD_ACTIVE)
    {
        return NULL;
    }

    /* check if force bit is involved */
    if(p_md1->mode & BTM_PM_MD_FORCE)
    {
        *p_res = *p_md1;
        p_res->mode &= ~BTM_PM_MD_FORCE;
        return p_res;
    }

    if(p_md2->mode & BTM_PM_MD_FORCE)
    {
        *p_res = *p_md2;
        p_res->mode &= ~BTM_PM_MD_FORCE;
        return p_res;
    }

    res = (p_md1->mode - 1) * BTM_PM_NUM_SET_MODES + (p_md2->mode - 1);
    res = btm_pm_md_comp_matrix[res];
    switch(res)
    {
    case BTM_PM_GET_MD1:
        *p_res = *p_md1;
        return p_md1;

    case BTM_PM_GET_MD2:
        *p_res = *p_md2;
        return p_md2;

    case BTM_PM_GET_COMP:
        p_res->mode = p_md1->mode;
        /* min of the two */
        p_res->max  = (p_md1->max < p_md2->max)? (p_md1->max) : (p_md2->max);
        /* max of the two */
        p_res->min  = (p_md1->min > p_md2->min)? (p_md1->min) : (p_md2->min);

        /* the intersection is NULL */
        if( p_res->max < p_res->min)
            return NULL;

        if(p_res->mode == BTM_PM_MD_SNIFF)
        {
            /* max of the two */
            p_res->attempt  = (p_md1->attempt > p_md2->attempt)? (p_md1->attempt) : (p_md2->attempt);
            p_res->timeout  = (p_md1->timeout > p_md2->timeout)? (p_md1->timeout) : (p_md2->timeout);
        }
        return p_res;
    }
    return NULL;
}

/*******************************************************************************
**
** Function     btm_pm_get_set_mode
** Description  get the resulting mode from the registered parties, then compare it
**              with the requested mode, if the command is from an unregistered party.
** Returns      void
**
*******************************************************************************/
static tBTM_PM_MODE btm_pm_get_set_mode(UINT8 pm_id, tBTM_PM_MCB *p_cb, tBTM_PM_PWR_MD *p_mode, tBTM_PM_PWR_MD *p_res)
{
    int   xx, loop_max;
    tBTM_PM_PWR_MD *p_md = NULL;

    if(p_mode != NULL && p_mode->mode & BTM_PM_MD_FORCE)
    {
        *p_res = *p_mode;
        p_res->mode &= ~BTM_PM_MD_FORCE;
        return p_res->mode;
    }

    if(!p_mode)
        loop_max = BTM_MAX_PM_RECORDS+1;
    else
        loop_max = BTM_MAX_PM_RECORDS;

    for( xx=0; xx<loop_max; xx++)
    {
        /* g through all the registered "set" parties */
        if(btm_cb.pm_reg_db[xx].mask & BTM_PM_REG_SET)
        {
            if(p_cb->req_mode[xx].mode == BTM_PM_MD_ACTIVE)
            {
                /* if at least one registered (SET) party says ACTIVE, stay active */
                return BTM_PM_MD_ACTIVE;
            }
            else
            {
                /* if registered parties give conflicting information, stay active */
                if( (btm_pm_compare_modes(p_md, &p_cb->req_mode[xx], p_res)) == NULL)
                    return BTM_PM_MD_ACTIVE;
                p_md = p_res;
            }
        }
    }

    /* if the resulting mode is NULL(nobody registers SET), use the requested mode */
    if(p_md == NULL)
    {
        if(p_mode)
            *p_res = *((tBTM_PM_PWR_MD *)p_mode);
        else /* p_mode is NULL when btm_pm_snd_md_req is called from btm_pm_proc_mode_change */
            return BTM_PM_MD_ACTIVE;
    }
    else
    {
        /* if the command is from unregistered party,
           compare the resulting mode from registered party*/
        if( (pm_id == BTM_PM_SET_ONLY_ID) &&
            ((btm_pm_compare_modes(p_mode, p_md, p_res)) == NULL) )
            return BTM_PM_MD_ACTIVE;
    }

    return p_res->mode;
}

/*******************************************************************************
**
** Function     btm_pm_snd_md_req
** Description  get the resulting mode and send the resuest to host controller
** Returns      tBTM_STATUS
**, BOOLEAN *p_chg_ind
*******************************************************************************/
static tBTM_STATUS btm_pm_snd_md_req(UINT8 pm_id, int link_ind, tBTM_PM_PWR_MD *p_mode)
{
    tBTM_PM_PWR_MD  md_res;
    tBTM_PM_MODE    mode;
    tBTM_PM_MCB *p_cb = &btm_cb.pm_mode_db[link_ind];
    BOOLEAN      chg_ind = FALSE;

    mode = btm_pm_get_set_mode(pm_id, p_cb, p_mode, &md_res);
    md_res.mode = mode;

#if BTM_PM_DEBUG == TRUE
    BTM_TRACE_DEBUG2( "btm_pm_snd_md_req link_ind:%d, mode: %d",
        link_ind, mode);
#endif

    if( p_cb->state == mode)
    {
        /* already in the resulting mode */
        if( (mode == BTM_PM_MD_ACTIVE) ||
            ((md_res.max >= p_cb->interval) && (md_res.min <= p_cb->interval)) )
            return BTM_CMD_STORED;
        /* Otherwise, needs to wake, then sleep */
        chg_ind = TRUE;
    }
    p_cb->chg_ind = chg_ind;

     /* cannot go directly from current mode to resulting mode. */
    if( mode != BTM_PM_MD_ACTIVE && p_cb->state != BTM_PM_MD_ACTIVE)
        p_cb->chg_ind = TRUE; /* needs to wake, then sleep */

    if(p_cb->chg_ind == TRUE) /* needs to wake first */
        md_res.mode = BTM_PM_MD_ACTIVE;
#if (BTM_SSR_INCLUDED == TRUE)
    else if(BTM_PM_MD_SNIFF == md_res.mode && p_cb->max_lat)
    {
        btsnd_hcic_sniff_sub_rate(btm_cb.acl_db[link_ind].hci_handle, p_cb->max_lat,
                                  p_cb->min_rmt_to, p_cb->min_loc_to);
        p_cb->max_lat = 0;
    }
#endif
    /* Default is failure */
    btm_cb.pm_pend_link = MAX_L2CAP_LINKS;

    /* send the appropriate HCI command */
    btm_cb.pm_pend_id   = pm_id;

#if BTM_PM_DEBUG == TRUE
    BTM_TRACE_DEBUG2("btm_pm_snd_md_req state:0x%x, link_ind: %d", p_cb->state, link_ind);
#endif
    switch(md_res.mode)
    {
    case BTM_PM_MD_ACTIVE:
        switch(p_cb->state)
        {
        case BTM_PM_MD_SNIFF:
            if (btsnd_hcic_exit_sniff_mode(btm_cb.acl_db[link_ind].hci_handle))
            {
                btm_cb.pm_pend_link = link_ind;
            }
            break;
        case BTM_PM_MD_PARK:
            if (btsnd_hcic_exit_park_mode(btm_cb.acl_db[link_ind].hci_handle))
            {
                btm_cb.pm_pend_link = link_ind;
            }
            break;
        default:
            /* Failure btm_cb.pm_pend_link = MAX_L2CAP_LINKS */
            break;
        }
        break;

    case BTM_PM_MD_HOLD:
        if (btsnd_hcic_hold_mode (btm_cb.acl_db[link_ind].hci_handle,
                                  md_res.max, md_res.min))
        {
            btm_cb.pm_pend_link = link_ind;
        }
        break;

    case BTM_PM_MD_SNIFF:
        if (btsnd_hcic_sniff_mode (btm_cb.acl_db[link_ind].hci_handle,
                                   md_res.max, md_res.min, md_res.attempt,
                                   md_res.timeout))
        {
            btm_cb.pm_pend_link = link_ind;
        }
        break;

    case BTM_PM_MD_PARK:
        if (btsnd_hcic_park_mode (btm_cb.acl_db[link_ind].hci_handle,
                                  md_res.max, md_res.min))
        {
            btm_cb.pm_pend_link = link_ind;
        }
        break;
    default:
        /* Failure btm_cb.pm_pend_link = MAX_L2CAP_LINKS */
        break;
    }

    if(btm_cb.pm_pend_link == MAX_L2CAP_LINKS)
    {
        /* the command was not sent */
#if BTM_PM_DEBUG == TRUE
        BTM_TRACE_DEBUG1( "pm_pend_link: %d",btm_cb.pm_pend_link);
#endif
        return (BTM_NO_RESOURCES);
    }

    return BTM_CMD_STARTED;
}

/*******************************************************************************
**
** Function         btm_pm_check_stored
**
** Description      This function is called when an HCI command status event occurs
**                  to check if there's any PM command issued while waiting for
**                  HCI command status.
**
** Returns          none.
**
*******************************************************************************/
static void btm_pm_check_stored(void)
{
    int     xx;
    for(xx=0; xx<MAX_L2CAP_LINKS; xx++)
    {
        if(btm_cb.pm_mode_db[xx].state & BTM_PM_STORED_MASK)
        {
            btm_cb.pm_mode_db[xx].state &= ~BTM_PM_STORED_MASK;
            BTM_TRACE_DEBUG1( "btm_pm_check_stored :%d", xx);
            btm_pm_snd_md_req(BTM_PM_SET_ONLY_ID, xx, NULL);
            break;
        }
    }
}


/*******************************************************************************
**
** Function         btm_pm_proc_cmd_status
**
** Description      This function is called when an HCI command status event occurs
**                  for power manager related commands.
**
** Input Parms      status - status of the event (HCI_SUCCESS if no errors)
**
** Returns          none.
**
*******************************************************************************/
void btm_pm_proc_cmd_status(UINT8 status)
{
    tBTM_PM_MCB     *p_cb;
    tBTM_PM_STATUS  pm_status;

    if(btm_cb.pm_pend_link >= MAX_L2CAP_LINKS)
        return;

    p_cb = &btm_cb.pm_mode_db[btm_cb.pm_pend_link];

    if(status == HCI_SUCCESS)
    {
        p_cb->state = BTM_PM_ST_PENDING;
        pm_status = BTM_PM_STS_PENDING;
#if BTM_PM_DEBUG == TRUE
        BTM_TRACE_DEBUG1( "btm_pm_proc_cmd_status new state:0x%x", p_cb->state);
#endif
    }
    else /* the command was not successfull. Stay in the same state */
    {
        pm_status = BTM_PM_STS_ERROR;
    }

    /* notify the caller is appropriate */
    if( (btm_cb.pm_pend_id != BTM_PM_SET_ONLY_ID) &&
        (btm_cb.pm_reg_db[btm_cb.pm_pend_id].mask & BTM_PM_REG_NOTIF) )
    {
        (*btm_cb.pm_reg_db[btm_cb.pm_pend_id].cback)(btm_cb.acl_db[btm_cb.pm_pend_link].remote_addr, pm_status, 0, status);
    }

    /* no pending cmd now */
#if BTM_PM_DEBUG == TRUE
    BTM_TRACE_DEBUG3( "btm_pm_proc_cmd_status state:0x%x, pm_pend_link: %d(new: %d)",
        p_cb->state, btm_cb.pm_pend_link, MAX_L2CAP_LINKS);
#endif
    btm_cb.pm_pend_link = MAX_L2CAP_LINKS;

    btm_pm_check_stored();
}

/*******************************************************************************
**
** Function         btm_process_mode_change
**
** Description      This function is called when an HCI mode change event occurs.
**
** Input Parms      hci_status - status of the event (HCI_SUCCESS if no errors)
**                  hci_handle - connection handle associated with the change
**                  mode - HCI_MODE_ACTIVE, HCI_MODE_HOLD, HCI_MODE_SNIFF, or HCI_MODE_PARK
**                  interval - number of baseband slots (meaning depends on mode)
**
** Returns          none.
**
*******************************************************************************/
void btm_pm_proc_mode_change (UINT8 hci_status, UINT16 hci_handle, UINT8 mode, UINT16 interval)
{
    tACL_CONN   *p;
    tBTM_PM_MCB *p_cb = NULL;
    int xx, yy, zz;
    tBTM_PM_STATE  old_state;
    tL2C_LCB        *p_lcb;

    /* get the index to acl_db */
    if ((xx = btm_handle_to_acl_index(hci_handle)) >= MAX_L2CAP_LINKS)
        return;

    p = &btm_cb.acl_db[xx];

    /*** 2035 and 2045 work around:  If mode is active and coming out of a SCO disconnect, restore packet types ***/
    if (mode == HCI_MODE_ACTIVE)
    {
        if(BTM_GetNumScoLinks() == 0)
        {
            if(p->restore_pkt_types)
    {
        BTM_TRACE_DEBUG3("btm mode change AFTER unsniffing; hci hdl 0x%x, types 0x%02x/0x%02x",
                            hci_handle, p->pkt_types_mask, p->restore_pkt_types);
        p->pkt_types_mask = p->restore_pkt_types;
        p->restore_pkt_types = 0;   /* Only exists while SCO is active */
        btsnd_hcic_change_conn_type (p->hci_handle, p->pkt_types_mask);
    }
#if (BTM_PM_SNIFF_SLOT_WORK_AROUND == TRUE)
            else
            {
                BTM_TRACE_DEBUG2("btm mode change AFTER unsniffing; hci hdl 0x%x, types 0x%02x",
                                    hci_handle, btm_cb.btm_acl_pkt_types_supported);
                btm_set_packet_types (p, btm_cb.btm_acl_pkt_types_supported);
            }
#endif
        }
#if (BTM_PM_SNIFF_SLOT_WORK_AROUND == TRUE)
        else
        {
            /* Mode changed from Sniff to Active while SCO is open. */
            /* Packet types of active mode, not sniff mode, should be used for ACL when SCO is closed. */
            p->restore_pkt_types = btm_cb.btm_acl_pkt_types_supported;

            /* Exclude packet types not supported by the peer */
            btm_acl_chk_peer_pkt_type_support (p, &p->restore_pkt_types);
        }
#endif
    }
#if (BTM_PM_SNIFF_SLOT_WORK_AROUND == TRUE)
    else if (mode == HCI_MODE_SNIFF)
    {
        BTM_TRACE_DEBUG1("btm mode change to sniff; hci hdl 0x%x use single slot",
                            hci_handle);
        btm_set_packet_types (p, (HCI_PKT_TYPES_MASK_DM1 | HCI_PKT_TYPES_MASK_DH1));
    }
#endif

    /* update control block */
    p_cb = &(btm_cb.pm_mode_db[xx]);
    old_state       = p_cb->state;
    p_cb->state     = mode;
    p_cb->interval  = interval;
#if BTM_PM_DEBUG == TRUE
    BTM_TRACE_DEBUG2( "btm_pm_proc_mode_change new state:0x%x (old:0x%x)", p_cb->state, old_state);
#endif

    if ((p_cb->state == HCI_MODE_ACTIVE) &&
        ((p_lcb = l2cu_find_lcb_by_bd_addr (p->remote_addr)) != NULL))
    {
        /* There might be any pending packets due to SNIFF or PENDING state */
        /* Trigger L2C to start transmission of the pending packets.        */
        BTM_TRACE_DEBUG0 ("btm mode change to active; check l2c_link for outgoing packets");
        l2c_link_check_send_pkts (p_lcb, NULL, NULL);

        //btu_stop_timer (&p_lcb->timer_entry);
    }

    /* notify registered parties */
    for(yy=0; yy<=BTM_MAX_PM_RECORDS; yy++)
    {
        /* set req_mode  HOLD mode->ACTIVE */
        if( (mode == BTM_PM_MD_ACTIVE) && (p_cb->req_mode[yy].mode == BTM_PM_MD_HOLD) )
            p_cb->req_mode[yy].mode = BTM_PM_MD_ACTIVE;
    }

    /* new request has been made. - post a message to BTU task */
    if(old_state & BTM_PM_STORED_MASK)
    {
#if BTM_PM_DEBUG == TRUE
        BTM_TRACE_DEBUG1( "btm_pm_proc_mode_change: Sending stored req:%d", xx);
#endif
        btm_pm_snd_md_req(BTM_PM_SET_ONLY_ID, xx, NULL);
    }
    else
    {
        for(zz=0; zz<MAX_L2CAP_LINKS; zz++)
        {
            if(btm_cb.pm_mode_db[zz].chg_ind == TRUE)
            {
#if BTM_PM_DEBUG == TRUE
                BTM_TRACE_DEBUG1( "btm_pm_proc_mode_change: Sending PM req :%d", zz);
#endif
                btm_pm_snd_md_req(BTM_PM_SET_ONLY_ID, zz, NULL);
                break;
            }
        }
    }


    /* notify registered parties */
    for(yy=0; yy<BTM_MAX_PM_RECORDS; yy++)
    {
        if(btm_cb.pm_reg_db[yy].mask & BTM_PM_REG_NOTIF)
        {
            (*btm_cb.pm_reg_db[yy].cback)( p->remote_addr, mode, interval, hci_status);
        }
    }

    /* If mode change was because of an active role switch or change link key */
    btm_cont_rswitch_or_chglinkkey(p, btm_find_dev(p->remote_addr), hci_status);
}

/*******************************************************************************
**
** Function         btm_pm_proc_ssr_evt
**
** Description      This function is called when an HCI sniff subrating event occurs.
**
** Returns          none.
**
*******************************************************************************/
#if (BTM_SSR_INCLUDED == TRUE)
void btm_pm_proc_ssr_evt (UINT8 *p, UINT16 evt_len)
{
    UINT8       status;
    UINT16      handle;
    UINT16      max_tx_lat, max_rx_lat;
    int         xx, yy;
    tBTM_PM_MCB *p_cb;
    tACL_CONN   *p_acl=NULL;
    UINT16      use_ssr = TRUE;

    STREAM_TO_UINT8 (status, p);

    STREAM_TO_UINT16 (handle, p);
    /* get the index to acl_db */
    if ((xx = btm_handle_to_acl_index(handle)) >= MAX_L2CAP_LINKS)
        return;

    STREAM_TO_UINT16 (max_tx_lat, p);
    STREAM_TO_UINT16 (max_rx_lat, p);
    p_cb = &(btm_cb.pm_mode_db[xx]);

    p_acl = &btm_cb.acl_db[xx];
    if(p_cb->interval == max_rx_lat)
    {
        /* using legacy sniff */
        use_ssr = FALSE;
    }

    /* notify registered parties */
    for(yy=0; yy<BTM_MAX_PM_RECORDS; yy++)
    {
        if(btm_cb.pm_reg_db[yy].mask & BTM_PM_REG_NOTIF)
        {
            if( p_acl)
            {
                (*btm_cb.pm_reg_db[yy].cback)( p_acl->remote_addr, BTM_PM_STS_SSR, use_ssr, status);
            }
        }
    }
}
#endif
#else /* BTM_PWR_MGR_INCLUDED == TRUE */

/*******************************************************************************
**
** Functions        BTM_PmRegister, BTM_SetPowerMode, and BTM_ReadPowerMode
**
** Description      Stubbed versions for BTM_PWR_MGR_INCLUDED = FALSE
**
** Returns          BTM_MODE_UNSUPPORTED.
**
*******************************************************************************/
tBTM_STATUS BTM_PmRegister (UINT8 mask, UINT8 *p_pm_id, tBTM_PM_STATUS_CBACK *p_cb)
{
    return BTM_MODE_UNSUPPORTED;
}

tBTM_STATUS BTM_SetPowerMode (UINT8 pm_id, BD_ADDR remote_bda, tBTM_PM_PWR_MD *p_mode)
{
    return BTM_MODE_UNSUPPORTED;
}

tBTM_STATUS BTM_ReadPowerMode (BD_ADDR remote_bda, tBTM_PM_MODE *p_mode)
{
    return BTM_MODE_UNSUPPORTED;
}

#endif

/*******************************************************************************
**
** Function         BTM_IsPowerManagerOn
**
** Description      This function is called to check if power manager is included.
**                  in the BTE version.
**
** Returns          BTM_PWR_MGR_INCLUDED.
**
*******************************************************************************/
BOOLEAN BTM_IsPowerManagerOn (void)
{
    return BTM_PWR_MGR_INCLUDED;
}