if_ath_btcoex_mci.c

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/*-
 * Copyright (c) 2014 Qualcomm Atheros, Inc.
 * Copyright (c) 2016 Adrian Chadd <adrian@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGES.
 *
 * $FreeBSD$
 */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
 
/*
 * This implements the MCI bluetooth coexistence handling.
 */
#include "opt_ath.h"
#include "opt_inet.h"
#include "opt_wlan.h"
 
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/errno.h>
 
#include <machine/bus.h>
#include <machine/resource.h>
 
#include <sys/bus.h>
 
#include <sys/socket.h>
 
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/if_arp.h>
#include <net/ethernet.h>               /* XXX for ether_sprintf */
 
#include <net80211/ieee80211_var.h>
 
#include <net/bpf.h>
 
#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif
 
#include <dev/ath/if_athvar.h>
#include <dev/ath/if_ath_debug.h>
#include <dev/ath/if_ath_descdma.h>
#include <dev/ath/if_ath_btcoex.h>
 
#include <dev/ath/if_ath_btcoex_mci.h>
 
MALLOC_DECLARE(M_ATHDEV);
 
#define ATH_MCI_GPM_MAX_ENTRY           16
#define ATH_MCI_GPM_BUF_SIZE            (ATH_MCI_GPM_MAX_ENTRY * 16)
#define ATH_MCI_SCHED_BUF_SIZE          (16 * 16) /* 16 entries, 4 dword each */
 
static void ath_btcoex_mci_update_wlan_channels(struct ath_softc *sc);
 
int
ath_btcoex_mci_attach(struct ath_softc *sc)
{
        int buflen, error;
 
        buflen = ATH_MCI_GPM_BUF_SIZE + ATH_MCI_SCHED_BUF_SIZE;
        error = ath_descdma_alloc_desc(sc, &sc->sc_btcoex.buf, NULL,
            "MCI bufs", buflen, 1);
        if (error != 0) {
                device_printf(sc->sc_dev, "%s: failed to alloc MCI RAM\n",
                    __func__);
                return (error);
        }
 
        /* Yes, we're going to do bluetooth MCI coex */
        sc->sc_btcoex_mci = 1;
 
        /* Initialise the wlan channel mapping */
        sc->sc_btcoex.wlan_channels[0] = 0x00000000;
        sc->sc_btcoex.wlan_channels[1] = 0xffffffff;
        sc->sc_btcoex.wlan_channels[2] = 0xffffffff;
        sc->sc_btcoex.wlan_channels[3] = 0x7fffffff;
 
        /*
         * Ok, so the API is a bit odd. It assumes sched_addr is
         * after gpm_addr, and it does math to figure out the right
         * sched_buf pointer.
         *
         * So, set gpm_addr to buf, sched_addr to gpm_addr + ATH_MCI_GPM_BUF_SIZE,
         * the HAL call with do (gpm_buf + (sched_addr - gpm_addr)) to
         * set sched_buf, and we're "golden".
         *
         * Note, it passes in 'len' here (gpm_len) as
         * ATH_MCI_GPM_BUF_SIZE >> 4.  My guess is that it's 16
         * bytes per entry and we're storing 16 entries.
         */
        sc->sc_btcoex.gpm_buf = (void *) sc->sc_btcoex.buf.dd_desc;
        sc->sc_btcoex.sched_buf = sc->sc_btcoex.gpm_buf +
            ATH_MCI_GPM_BUF_SIZE;
 
        sc->sc_btcoex.gpm_paddr = sc->sc_btcoex.buf.dd_desc_paddr;
        sc->sc_btcoex.sched_paddr = sc->sc_btcoex.gpm_paddr +
            ATH_MCI_GPM_BUF_SIZE;
 
        /* memset the gpm buffer with MCI_GPM_RSVD_PATTERN */
        memset(sc->sc_btcoex.gpm_buf, 0xfe, buflen);
 
        /*
         * This is an unfortunate x86'ism in the HAL - the
         * HAL code expects the passed in buffer to be
         * coherent, and doesn't implement /any/ kind
         * of buffer sync operations at all.
         *
         * So, this code will only work on dma coherent buffers
         * and will behave poorly on non-coherent systems.
         * Fixing this would require some HAL surgery so it
         * actually /did/ the buffer flushing as appropriate.
         */
        ath_hal_btcoex_mci_setup(sc->sc_ah,
            sc->sc_btcoex.gpm_paddr,
            sc->sc_btcoex.gpm_buf,
            ATH_MCI_GPM_BUF_SIZE >> 4,
            sc->sc_btcoex.sched_paddr);
 
        return (0);
}
 
/*
 * Detach btcoex from the given interface
 */
int
ath_btcoex_mci_detach(struct ath_softc *sc)
{
 
        ath_hal_btcoex_mci_detach(sc->sc_ah);
        ath_descdma_cleanup(sc, &sc->sc_btcoex.buf, NULL);
        return (0);
}
 
/*
 * Configure or disable bluetooth coexistence on the given channel.
 *
 * For MCI, we just use the top-level enable/disable flag, and
 * then the MCI reset / channel update path will configure things
 * appropriately based on the current band.
 */
int
ath_btcoex_mci_enable(struct ath_softc *sc,
    const struct ieee80211_channel *chan)
{
 
        /*
         * Always reconfigure stomp-all for now, so wlan wins.
         *
         * The default weights still don't allow beacons to win,
         * so unless you set net.wlan.X.bmiss_max to something higher,
         * net80211 will disconnect you during a HCI INQUIRY command.
         *
         * The longer-term solution is to dynamically adjust whether
         * bmiss happens based on bluetooth requirements, and look at
         * making the individual stomp bits configurable.
         */
        ath_hal_btcoex_set_weights(sc->sc_ah, HAL_BT_COEX_STOMP_ALL);
 
        /*
         * update wlan channels so the firmware knows what channels it
         * can/can't use.
         */
        ath_btcoex_mci_update_wlan_channels(sc);
 
        return (0);
}
 
/*
 * XXX TODO: turn into general btcoex, and then make this
 * the MCI specific bits.
 */
static void
ath_btcoex_mci_event(struct ath_softc *sc, ATH_BT_COEX_EVENT nevent,
    void *param)
{
 
        if (! sc->sc_btcoex_mci)
                return;
 
        /*
         * Check whether we need to flush our local profile cache.
         * If we do, then at (XXX TODO) we should flush our state,
         * then wait for the MCI response with the updated profile list.
         */
        if (ath_hal_btcoex_mci_state(sc->sc_ah,
            HAL_MCI_STATE_NEED_FLUSH_BT_INFO, NULL) != 0) {
                uint32_t data = 0;
 
                if (ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_ENABLE, NULL) != 0) {
                        DPRINTF(sc, ATH_DEBUG_BTCOEX,
                            "(MCI) Flush BT profile\n");
                        /*
                         * XXX TODO: flush profile state on the ath(4)
                         * driver side; subsequent messages will come
                         * through with the current list of active
                         * profiles.
                         */
                        ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_NEED_FLUSH_BT_INFO, &data);
                        ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_SEND_STATUS_QUERY, NULL);
                }
        }
        if (nevent == ATH_COEX_EVENT_BT_NOOP) {
                DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) BT_NOOP\n");
                return;
        }
}
 
static void
ath_btcoex_mci_send_gpm(struct ath_softc *sc, uint32_t *payload)
{
 
        ath_hal_btcoex_mci_send_message(sc->sc_ah, MCI_GPM, 0, payload, 16,
            AH_FALSE, AH_TRUE);
}
 
/*
 * This starts a BT calibration.  It requires a chip reset.
 */
static int
ath_btcoex_mci_bt_cal_do(struct ath_softc *sc, int tx_timeout, int rx_timeout)
{
 
        device_printf(sc->sc_dev, "%s: TODO!\n", __func__);
        return (0);
}
 
static void
ath_btcoex_mci_cal_msg(struct ath_softc *sc, uint8_t opcode,
    uint8_t *rx_payload)
{
        uint32_t payload[4] = {0, 0, 0, 0};
 
        switch (opcode) {
        case MCI_GPM_BT_CAL_REQ:
                DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) receive BT_CAL_REQ\n");
                if (ath_hal_btcoex_mci_state(sc->sc_ah, HAL_MCI_STATE_BT,
                    NULL) == MCI_BT_AWAKE) {
                        ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_SET_BT_CAL_START, NULL);
                        ath_btcoex_mci_bt_cal_do(sc, 1000, 1000);
                } else {
                        DPRINTF(sc, ATH_DEBUG_BTCOEX,
                            "(MCI) State mismatches: %d\n",
                            ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_BT, NULL));
                }
                break;
        case MCI_GPM_BT_CAL_DONE:
                DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) receive BT_CAL_DONE\n");
                if (ath_hal_btcoex_mci_state(sc->sc_ah, HAL_MCI_STATE_BT,
                    NULL) == MCI_BT_CAL) {
                        DPRINTF(sc, ATH_DEBUG_BTCOEX,
                            "(MCI) ERROR ILLEGAL!\n");
                } else {
                        DPRINTF(sc, ATH_DEBUG_BTCOEX,
                            "(MCI) BT not in CAL state.\n");
                }
                break;
        case MCI_GPM_BT_CAL_GRANT:
                DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) receive BT_CAL_GRANT\n");
                /* Send WLAN_CAL_DONE for now */
                DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) Send WLAN_CAL_DONE\n");
                MCI_GPM_SET_CAL_TYPE(payload, MCI_GPM_WLAN_CAL_DONE);
                ath_btcoex_mci_send_gpm(sc, &payload[0]);
                break;
        default:
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) Unknown GPM CAL message.\n");
                break;
        }
}
 
/*
 * Update the bluetooth channel map.
 *
 * This map tells the bluetooth device which bluetooth channels
 * are available for data.
 *
 * For 5GHz, all channels are available.
 * For 2GHz, the current wifi channel range is blocked out,
 *   and the rest are available.
 *
 * This narrows which frequencies are used by the device when
 * it initiates a transfer, thus hopefully reducing the chances
 * of collisions (both hopefully on the current device and
 * other devices in the same channel.)
 */
static void
ath_btcoex_mci_update_wlan_channels(struct ath_softc *sc)
{
        struct ieee80211com *ic = &sc->sc_ic;
        struct ieee80211_channel *chan = ic->ic_curchan;
        uint32_t channel_info[4] =
            { 0x00000000, 0xffffffff, 0xffffffff, 0x7fffffff };
        int32_t wl_chan, bt_chan, bt_start = 0, bt_end = 79;
 
        /* BT channel frequency is 2402 + k, k = 0 ~ 78 */
        if (IEEE80211_IS_CHAN_2GHZ(chan)) {
                wl_chan = chan->ic_freq - 2402;
                if (IEEE80211_IS_CHAN_HT40U(chan)) {
                        bt_start = wl_chan - 10;
                        bt_end = wl_chan + 30;
                } else if (IEEE80211_IS_CHAN_HT40D(chan)) {
                        bt_start = wl_chan - 30;
                        bt_end = wl_chan + 10;
                } else {
                        /* Assume 20MHz */
                        bt_start = wl_chan - 10;
                        bt_end = wl_chan + 10;
                }
 
                bt_start -= 7;
                bt_end += 7;
 
                if (bt_start < 0) {
                        bt_start = 0;
                }
                if (bt_end > MCI_NUM_BT_CHANNELS) {
                        bt_end = MCI_NUM_BT_CHANNELS;
                }
                DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) WLAN use channel %d\n",
                    chan->ic_freq);
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) mask BT channel %d - %d\n", bt_start, bt_end);
                for (bt_chan = bt_start; bt_chan < bt_end; bt_chan++) {
                        MCI_GPM_CLR_CHANNEL_BIT(&channel_info[0], bt_chan);
                }
        } else {
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) WLAN not use any 2G channel, unmask all for BT\n");
        }
        ath_hal_btcoex_mci_state(sc->sc_ah, HAL_MCI_STATE_SEND_WLAN_CHANNELS,
            &channel_info[0]);
}
 
static void
ath_btcoex_mci_coex_msg(struct ath_softc *sc, uint8_t opcode,
    uint8_t *rx_payload)
{
        uint32_t version;
        uint8_t major;
        uint8_t minor;
        uint32_t seq_num;
 
        switch (opcode) {
        case MCI_GPM_COEX_VERSION_QUERY:
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) Recv GPM COEX Version Query.\n");
                version = ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_SEND_WLAN_COEX_VERSION, NULL);
                break;
 
        case MCI_GPM_COEX_VERSION_RESPONSE:
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) Recv GPM COEX Version Response.\n");
                major = *(rx_payload + MCI_GPM_COEX_B_MAJOR_VERSION);
                minor = *(rx_payload + MCI_GPM_COEX_B_MINOR_VERSION);
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) BT Coex version: %d.%d\n", major, minor);
                version = (major << 8) + minor;
                version = ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_SET_BT_COEX_VERSION, &version);
                break;
 
        case MCI_GPM_COEX_STATUS_QUERY:
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) Recv GPM COEX Status Query = 0x%02x.\n",
                    *(rx_payload + MCI_GPM_COEX_B_WLAN_BITMAP));
                ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_SEND_WLAN_CHANNELS, NULL);
                break;
 
        case MCI_GPM_COEX_BT_PROFILE_INFO:
                /*
                 * XXX TODO: here is where we'd parse active profile
                 * info and make driver/stack choices as appropriate.
                 */
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) TODO: Recv GPM COEX BT_Profile_Info.\n");
                break;
 
        case MCI_GPM_COEX_BT_STATUS_UPDATE:
                seq_num = *((uint32_t *)(rx_payload + 12));
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) Recv GPM COEX BT_Status_Update: SEQ=%d\n",
                    seq_num);
                break;
 
        default:
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) Unknown GPM COEX message = 0x%02x\n", opcode);
                break;
        }
}
 
void
ath_btcoex_mci_intr(struct ath_softc *sc)
{
        uint32_t mciInt, mciIntRxMsg;
        uint32_t offset, subtype, opcode;
        uint32_t *pGpm;
        uint32_t more_data = HAL_MCI_GPM_MORE;
        int8_t value_dbm;
        bool skip_gpm = false;
 
        DPRINTF(sc, ATH_DEBUG_BTCOEX, "%s: called\n", __func__);
 
        ath_hal_btcoex_mci_get_interrupt(sc->sc_ah, &mciInt, &mciIntRxMsg);
 
        if (ath_hal_btcoex_mci_state(sc->sc_ah, HAL_MCI_STATE_ENABLE,
            NULL) == 0) {
                ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_INIT_GPM_OFFSET, NULL);
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) INTR but MCI_disabled\n");
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) MCI interrupt: mciInt = 0x%x, mciIntRxMsg = 0x%x\n",
                    mciInt, mciIntRxMsg);
                return;
        }
 
        if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_REQ_WAKE) {
                uint32_t payload4[4] = { 0xffffffff, 0xffffffff, 0xffffffff,
                    0xffffff00};
 
                /*
                 * The following REMOTE_RESET and SYS_WAKING used to sent
                 * only when BT wake up. Now they are always sent, as a
                 * recovery method to reset BT MCI's RX alignment.
                 */
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) 1. INTR Send REMOTE_RESET\n");
                ath_hal_btcoex_mci_send_message(sc->sc_ah,
                    MCI_REMOTE_RESET, 0, payload4, 16, AH_TRUE, AH_FALSE);
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) 1. INTR Send SYS_WAKING\n");
                ath_hal_btcoex_mci_send_message(sc->sc_ah,
                    MCI_SYS_WAKING, 0, NULL, 0, AH_TRUE, AH_FALSE);
 
                mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_REQ_WAKE;
                ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_RESET_REQ_WAKE, NULL);
 
                /* always do this for recovery and 2G/5G toggling and LNA_TRANS */
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) 1. Set BT state to AWAKE.\n");
                ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_SET_BT_AWAKE, NULL);
        }
 
        /* Processing SYS_WAKING/SYS_SLEEPING */
        if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_SYS_WAKING) {
                mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_SYS_WAKING;
                if (ath_hal_btcoex_mci_state(sc->sc_ah, HAL_MCI_STATE_BT,
                    NULL) == MCI_BT_SLEEP) {
                        if (ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_REMOTE_SLEEP, NULL) == MCI_BT_SLEEP) {
                                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                                    "(MCI) 2. BT stays in SLEEP mode.\n");
                        } else {
                                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                                    "(MCI) 2. Set BT state to AWAKE.\n");
                                ath_hal_btcoex_mci_state(sc->sc_ah,
                                    HAL_MCI_STATE_SET_BT_AWAKE, NULL);
                        }
                } else {
                        DPRINTF(sc, ATH_DEBUG_BTCOEX,
                            "(MCI) 2. BT stays in AWAKE mode.\n");
                }
        }
 
        if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_SYS_SLEEPING) {
                mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_SYS_SLEEPING;
                if (ath_hal_btcoex_mci_state(sc->sc_ah, HAL_MCI_STATE_BT,
                    NULL) == MCI_BT_AWAKE) {
                        if (ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_REMOTE_SLEEP, NULL) == MCI_BT_AWAKE) {
                                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                                    "(MCI) 3. BT stays in AWAKE mode.\n");
                        } else {
                                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                                    "(MCI) 3. Set BT state to SLEEP.\n");
                                ath_hal_btcoex_mci_state(sc->sc_ah,
                                    HAL_MCI_STATE_SET_BT_SLEEP, NULL);
                        }
                } else {
                        DPRINTF(sc, ATH_DEBUG_BTCOEX,
                            "(MCI) 3. BT stays in SLEEP mode.\n");
                }
        }
 
        /*
         * Recover from out-of-order / wrong-offset GPM messages.
         */
        if ((mciInt & HAL_MCI_INTERRUPT_RX_INVALID_HDR) ||
            (mciInt & HAL_MCI_INTERRUPT_CONT_INFO_TIMEOUT)) {
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) MCI RX broken, skip GPM messages\n");
                ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_RECOVER_RX, NULL);
                skip_gpm = true;
        }
 
        if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_SCHD_INFO) {
                mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_SCHD_INFO;
                offset = ath_hal_btcoex_mci_state(sc->sc_ah,
                    HAL_MCI_STATE_LAST_SCHD_MSG_OFFSET, NULL);
        }
 
        /*
         * Parse GPM messages.
         */
        if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_GPM) {
                mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_GPM;
 
                while (more_data == HAL_MCI_GPM_MORE) {
                        pGpm = (void *) sc->sc_btcoex.gpm_buf;
                        offset = ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_NEXT_GPM_OFFSET, &more_data);
 
                        if (offset == HAL_MCI_GPM_INVALID)
                                break;
                        pGpm += (offset >> 2);
                        /*
                         * The first DWORD is a timer.
                         * The real data starts from the second DWORD.
                         */
                        subtype = MCI_GPM_TYPE(pGpm);
                        opcode = MCI_GPM_OPCODE(pGpm);
 
                        if (!skip_gpm) {
                                if (MCI_GPM_IS_CAL_TYPE(subtype)) {
                                        ath_btcoex_mci_cal_msg(sc, subtype,
                                            (uint8_t*) pGpm);
                                } else {
                                        switch (subtype) {
                                        case MCI_GPM_COEX_AGENT:
                                                ath_btcoex_mci_coex_msg(sc,
                                                    opcode, (uint8_t*) pGpm);
                                        break;
                                        case MCI_GPM_BT_DEBUG:
                                                device_printf(sc->sc_dev,
                                                    "(MCI) TODO: GPM_BT_DEBUG!\n");
                                        break;
                                        default:
                                                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                                                    "(MCI) Unknown GPM message.\n");
                                                break;
                                        }
                                }
                        }
                        MCI_GPM_RECYCLE(pGpm);
                }
        }
 
        /*
         * This is monitoring/management information messages, so the driver
         * layer can hook in and dynamically adjust things like aggregation
         * size, expected bluetooth/wifi traffic throughput, etc.
         *
         * None of that is done right now; it just passes off the values
         * to the HAL so it can update its internal state as appropriate.
         * This code just prints out the values for debugging purposes.
         */
        if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_MONITOR) {
                if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_LNA_CONTROL) {
                        mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_LNA_CONTROL;
                        DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) LNA_CONTROL\n");
                }
                if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_LNA_INFO) {
                        mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_LNA_INFO;
                        DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) LNA_INFO\n");
                }
                if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_CONT_INFO) {
                        value_dbm = ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_CONT_RSSI_POWER, NULL);
 
                        mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_CONT_INFO;
                        if (ath_hal_btcoex_mci_state(sc->sc_ah,
                            HAL_MCI_STATE_CONT_TXRX, NULL)) {
                                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                                    "(MCI) CONT_INFO: (tx) pri = %d, pwr = %d dBm\n",
                                ath_hal_btcoex_mci_state(sc->sc_ah,
                                    HAL_MCI_STATE_CONT_PRIORITY, NULL),
                                    value_dbm);
                        } else {
                                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                                    "(MCI) CONT_INFO: (rx) pri = %d, rssi = %d dBm\n",
                                ath_hal_btcoex_mci_state(sc->sc_ah,
                                    HAL_MCI_STATE_CONT_PRIORITY, NULL),
                                    value_dbm);
                        }
                }
                if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_CONT_NACK) {
                        mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_CONT_NACK;
                        DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) CONT_NACK\n");
                }
                if (mciIntRxMsg & HAL_MCI_INTERRUPT_RX_MSG_CONT_RST) {
                        mciIntRxMsg &= ~HAL_MCI_INTERRUPT_RX_MSG_CONT_RST;
                        DPRINTF(sc, ATH_DEBUG_BTCOEX, "(MCI) CONT_RST\n");
                }
        }
 
        /*
         * Recover the state engine if we hit an invalid header/timeout.
         * This is the final part of GPT out-of-sync recovery.
         */
        if ((mciInt & HAL_MCI_INTERRUPT_RX_INVALID_HDR) ||
            (mciInt & HAL_MCI_INTERRUPT_CONT_INFO_TIMEOUT)) {
                ath_btcoex_mci_event(sc, ATH_COEX_EVENT_BT_NOOP, NULL);
                mciInt &= ~(HAL_MCI_INTERRUPT_RX_INVALID_HDR |
                    HAL_MCI_INTERRUPT_CONT_INFO_TIMEOUT);
        }
 
        if (mciIntRxMsg & 0xfffffffe) {
                DPRINTF(sc, ATH_DEBUG_BTCOEX,
                    "(MCI) Not processed IntRxMsg = 0x%x\n", mciIntRxMsg);
        }
}