aheros-txdma分析

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主要データ構造
struct ath_softc {
struct ath_hal          *sc_ah;     /* Atheros HAL */
struct ath_descdma      sc_txdma;       /* TX descriptors */ 
ath_bufhead             sc_txbuf;       /* transmit buffer */
struct ath_descdma      sc_txsdma; 
struct ath_buf          *sc_rxbufptr;
struct ath_rx_status    *sc_rxsptr;
u_int                   sc_txqsetup;    /* h/w queues setup */
struct ath_txq          sc_txq[HAL_NUM_TX_QUEUES];
HAL_TXQ_INFO            sc_beacon_qi;   /* adhoc only: beacon queue parameters */
u_int32_t               sc_txdesclen;   /* Tx descriptor length */
struct ath_descdma      sc_bdma;        /* beacon descriptors */
ath_bufhead             sc_bbuf;        /* beacon buffers */
u_int                   sc_bhalq;       /* HAL q for outgoing beacons */
}
/* Receive FIFO management */
struct ath_rx_edma {
    wbuf_t                  *rxfifo;
    u_int8_t                rxfifoheadindex;
    u_int8_t                rxfifotailindex;
    u_int8_t                rxfifodepth;        /* count of RXBPs pushed into fifo */
    u_int32_t               rxfifohwsize;       /* Rx FIFO size from HAL */
    ath_bufhead            rxqueue;
    spinlock_t              rxqlock;
};

/* Transmit Control Descriptor */
struct ar9300_txc {
    u_int32_t   ds_info;   /* descriptor information */
    u_int32_t   ds_link;   /* link pointer */
    u_int32_t   ds_data0;  /* data pointer to 1st buffer */
    u_int32_t   ds_ctl3;   /* DMA control 3  */
    u_int32_t   ds_data1;  /* data pointer to 2nd buffer */
    u_int32_t   ds_ctl5;   /* DMA control 5  */
    u_int32_t   ds_data2;  /* data pointer to 3rd buffer */
    u_int32_t   ds_ctl7;   /* DMA control 7  */
    u_int32_t   ds_data3;  /* data pointer to 4th buffer */
    u_int32_t   ds_ctl9;   /* DMA control 9  */
    u_int32_t   ds_ctl10;  /* DMA control 10 */
    u_int32_t   ds_ctl11;  /* DMA control 11 */
    u_int32_t   ds_ctl12;  /* DMA control 12 */
    u_int32_t   ds_ctl13;  /* DMA control 13 */
    u_int32_t   ds_ctl14;  /* DMA control 14 */
    u_int32_t   ds_ctl15;  /* DMA control 15 */
    u_int32_t   ds_ctl16;  /* DMA control 16 */
    u_int32_t   ds_ctl17;  /* DMA control 17 */
    u_int32_t   ds_ctl18;  /* DMA control 18 */
    u_int32_t   ds_ctl19;  /* DMA control 19 */
    u_int32_t   ds_ctl20;  /* DMA control 20 */
    u_int32_t   ds_ctl21;  /* DMA control 21 */
    u_int32_t   ds_ctl22;  /* DMA control 22 */
    u_int32_t   ds_pad[9]; /* pad to cache line (128 bytes/32 dwords) */
};
struct ath_desc {
    /*
     * The following definitions are passed directly
     * the hardware and managed by the HAL.  Drivers
     * should not touch those elements marked opaque.
     */
    u_int32_t    ds_link;    /* phys address of next descriptor */
    u_int32_t    ds_data;    /* phys address of data buffer */
    u_int32_t    ds_ctl0;    /* opaque DMA control 0 */
    u_int32_t    ds_ctl1;    /* opaque DMA control 1 */
    u_int32_t    ds_hw[20];    /* opaque h/w region */
    /*
     * The remaining definitions are managed by software;
     * these are valid only after the rx/tx process descriptor
     * methods return a non-EINPROGRESS  code.
     */
    union {
        struct ath_tx_status tx;/* xmit status */
        struct ath_rx_status rx;/* recv status */
        void    *stats;
    } ds_us;
    void        *ds_vdata;    /* virtual addr of data buffer */
} __packed;
struct ath_txq {
    u_int           axq_qnum;       /* hardware q number */
    u_int32_t       *axq_link;      /* link ptr in last TX desc */
    TAILQ_HEAD(, ath_buf)   axq_q;  /* transmit queue */
    spinlock_t      axq_lock;       /* lock on q and link */
    unsigned long   axq_lockflags;  /* intr state when must cli */
    u_int           axq_depth;      /* queue depth */
#if ATH_TX_BUF_FLOW_CNTL
    u_int           axq_minfree;    /* Number of free tx_bufs required in common buf pool */
    u_int           axq_num_buf_used; /* Number of used tx_buf for this q */
#endif
    u_int8_t        axq_aggr_depth; /* aggregates queued */
    u_int32_t       axq_totalqueued;/* total ever queued */
    u_int           axq_intrcnt;    /* count to determine if descriptor
                                     * should generate int on this txq.
                                     */
    /*
     * State for patching up CTS when bursting.
     */
    struct  ath_buf     *axq_linkbuf;   /* virtual addr of last buffer*/
    struct  ath_desc    *axq_lastdsWithCTS; /* first desc of the last descriptor
                                             * that contains CTS
                                             */
    struct  ath_desc    *axq_gatingds;  /* final desc of the gating desc
                                         * that determines whether lastdsWithCTS has
                                         * been DMA'ed or not
                                         */
    /*
     * Staging queue for frames awaiting a fast-frame pairing.
     */
    TAILQ_HEAD(axq_headtype, ath_buf) axq_stageq;
    TAILQ_HEAD(,ath_atx_ac) axq_acq;

#ifdef ATH_SUPERG_COMP
    /* scratch compression buffer */
    char                    *axq_compbuf;   /* scratch comp buffer */
    dma_addr_t              axq_compbufp;  /* scratch comp buffer (phys)*/
    u_int                   axq_compbufsz; /* scratch comp buffer size */
    OS_DMA_MEM_CONTEXT(axq_dmacontext)
#endif
#ifdef ATH_SWRETRY
    u_int                   axq_destmask:1; /*Destination mask for this queue*/
#endif
#if ATH_TX_POLL
    int            axq_lastq_tick; /* ticks when last packet queued */
#endif
    TAILQ_HEAD(, ath_buf)   axq_fifo[HAL_TXFIFO_DEPTH];
    u_int8_t                axq_headindex;
    u_int8_t                axq_tailindex;
    u_int                   irq_shared:1; /* This queue is shared by the irq_handler() */
/* BEGIN: added by SGR_TEAM 2011/11/29 for: tx       */
#if ATH_HW_TXQ_STUCK_WAR
    u_int8_t               tx_done_stuck_count;
#endif
/* END: added by SGR_TEAM 2011/11/29 for: tx       */
};
/*
 * per access-category aggregate tx state for a destination*/
typedef struct ath_atx_ac {
    int                     sched;      /* dest-ac is scheduled */
    int                     qnum;     /* H/W queue number associated with this AC */
    int                     hwqcnt;     /* count of pkts on hw queue */
#if ATH_SUPPORT_VOWEXT
    uint16_t                max_sch_penality;   /* Max Scheuding penality fo this ac */
    uint16_t                sch_penality_cnt;   /* Current pending scheduling penality count */
#endif
    TAILQ_ENTRY(ath_atx_ac) ac_qelem;   /* round-robin txq entry */
    TAILQ_HEAD(,ath_atx_tid)tid_q;      /* queue of TIDs with buffers */
    int                     filtered;   /* ac is filtered */
    TAILQ_ENTRY(ath_atx_ac) fltr_qelem; /* handle hwq filtering */
    TAILQ_HEAD(,ath_atx_tid)fltr_q;     /* queue of TIDs being filtered */
} ath_atx_ac_t;
/*
 * per TID aggregate tx state for a destination
 */
typedef struct ath_atx_tid {
    int               tidno;      /* TID number */
    u_int16_t         seq_start;  /* starting seq of BA window */
    u_int16_t         seq_next;   /* next seq to be used */
    u_int16_t         baw_size;   /* BA window size */
#ifdef ATH_HTC_TX_SCHED
    u_int8_t          tid_buf_cnt;
    u_int8_t          pad0;
#endif
    int               baw_head;   /* first un-acked tx buffer */
    int               baw_tail;   /* next unused tx buffer slot */
    u_int16_t         sched:1,    /* TID is scheduled */
                      filtered:1, /* TID has filtered pkts */
                      min_depth:2;/* num pkts that can be queued to h/w */
    int               paused;     /* TID is paused */
    int               cleanup_inprogress; /* this TID's aggr being torn down */
    TAILQ_HEAD(ath_tid_bq,ath_buf) buf_q;      /* pending buffers */
    TAILQ_ENTRY(ath_atx_tid)       tid_qelem;  /* round-robin tid entry */
    TAILQ_HEAD(,ath_buf)           fltr_q;     /* filtered buffers */
    TAILQ_ENTRY(ath_atx_tid)       fltr_qelem; /* handle hwq filtering */
    struct ath_node   *an;        /* parent node structure */
    struct ath_atx_ac *ac;        /* parent access category */
    u_int32_t         tx_buf_bitmap[TX_BUF_BITMAP_WORDS]; /* active tx frames */
    /*
     * ADDBA state
     */
    u_int32_t               addba_exchangecomplete:1,
                            addba_amsdusupported:1;
    int32_t                 addba_exchangeinprogress;
    struct ath_timer        addba_requesttimer;
    int                     addba_exchangeattempts;
    u_int16_t               addba_exchangestatuscode;
#ifdef VOW_TIDSCHED
    int qw;
    TAILQ_ENTRY(ath_atx_tid) wrr_tid_qelem; /* round-robin tid entry */
#endif
} ath_atx_tid_t;
struct ath_buf {
    TAILQ_ENTRY(ath_buf)    bf_list;
    struct ath_buf         *bf_lastbf;   /* last buf of this unit (a frame or an aggregate) */
    struct ath_buf         *bf_lastfrm;  /* last buf of this frame */
    struct ath_buf         *bf_next;     /* next subframe in the aggregate */
    struct ath_buf         *bf_rifslast; /* last buf for RIFS burst */
    void                   *bf_mpdu;     /* enclosing frame structure */
    void                   *bf_vdata;    /* virtual addr of data buffer */
    void                   *bf_node;     /* pointer to the node */
    void                   *bf_desc;     /* virtual addr of desc */
    dma_addr_t              bf_daddr;    /* physical addr of desc */
    dma_addr_t              bf_buf_addr[ATH_MAX_MAPS]; /* physical addr of data buffer */
    u_int32_t               bf_buf_len[ATH_MAX_MAPS];  /* len of data */
    u_int32_t               bf_status;
    u_int32_t               bf_flags;    /* tx descriptor flags */
#if ATH_SUPPORT_IQUE && ATH_SUPPORT_IQUE_EXT
    u_int32_t               bf_txduration;/* Tx duration of this buf */
#endif
    u_int16_t               bf_avail_buf;
    u_int16_t               bf_reftxpower;  /* reference tx power */
    struct ath_buf_state    bf_state;    /* buffer state */

    OS_DMA_MEM_CONTEXT(bf_dmacontext)    /* OS Specific DMA context */
#if 1//BR_RATECTRL_STAT_SUPPORT
    int bf_rate_set_type; // yangzhicong 2012-10-06 AP bridge
#endif 
};

struct ath_buf_state {
    int                     bfs_nframes;        /* # frames in aggregate */
    u_int16_t               bfs_al;             /* length of aggregate */
    u_int16_t               bfs_frmlen;         /* length of frame */
    int                     bfs_seqno;          /* sequence number */
    int                     bfs_tidno;          /* tid of this frame */
    int                     bfs_retries;        /* current retries */
    struct ath_rc_series    bfs_rcs[4];         /* rate series */
    int                     bfs_useminrate: 1;  /* use minrate */
    int                     bfs_ismcast: 1;     /* is mcast packet */
    int                     bfs_isdata: 1;      /* is a data frame/aggregate */
    int                     bfs_isaggr: 1;      /* is an aggregate */
    int                     bfs_isampdu: 1;     /* is an a-mpdu, aggregate or not */
    int                     bfs_ht: 1;          /* is an HT frame */
    int                     bfs_isretried: 1;   /* is retried */
    int                     bfs_isxretried: 1;  /* is excessive retried */
    int                     bfs_shpreamble: 1;  /* is short preamble */
    int                     bfs_isbar: 1;       /* is a BAR */
    int                     bfs_ispspoll: 1;    /* is a PS-Poll */
    int                     bfs_aggrburst: 1;   /* is a aggr burst */
    int                     bfs_calcairtime:1;  /* requests airtime be calculated when set for tx frame */
#ifdef ATH_SUPPORT_UAPSD
    int                     bfs_qosnulleosp:1;  /* is QoS null EOSP frame */
#endif
    int                     bfs_ispaprd:1;      /* is PAPRD frame */
    int                     bfs_isswaborted: 1; /* is the frame marked as sw aborted*/
#if ATH_SUPPORT_CFEND
    int                     bfs_iscfend:1;  /* is QoS null EOSP frame */
#endif
#ifdef ATH_SWRETRY
    int                     bfs_isswretry: 1;   /* is the frame marked for swretry*/
    int                     bfs_swretries;      /* number of swretries made*/
    int                     bfs_totaltries;     /* total tries including hw retries*/
#endif
    int                     bfs_qnum;           /* h/w queue number */
    int                     bfs_rifsburst_elem; /* RIFS burst/bar */
    int                     bfs_nrifsubframes;  /* # of elements in burst */
    HAL_KEY_TYPE            bfs_keytype;        /* key type use to encrypt this frame */
    u_int8_t                bfs_txbfstatus;     /* for TxBF , txbf status from TXS*/
};
struct ath_rc_series {
    u_int8_t    rix;
    u_int8_t    tries;
    u_int16_t   flags;
    u_int32_t   max4msframelen;
};
typedef struct {
    ath_node_t      an;         /* destination to sent to */
    int             if_id;      /* only valid for cab traffic */
    int             qnum;       /* h/w queue number */

    u_int           ismcast:1;  /* if it's a multicast frame */
    u_int           istxfrag:1; /* if it's a tx fragment */
    u_int           ismgmt:1;   /* if it's a management frame */
    u_int           isdata:1;   /* if it's a data frame */
    u_int           isqosdata:1; /* if it's a qos data frame */
    u_int           ps:1;       /* if one or more stations are in PS mode */
    u_int           shortPreamble:1; /* use short preamble */
    u_int           ht:1;       /* if it can be transmitted using HT */
    u_int           use_minrate:1; /* if this frame should transmitted using specified
                                    * mininum rate */
    u_int           isbar:1;    /* if it is a block ack request */
    u_int           ispspoll:1; /* if it is a PS-Poll frame */
    u_int           calcairtime:1; /* requests airtime be calculated when set for tx frame */
    u_int           iseap:1; /* Is this an EAP packet? */
#ifdef ATH_SUPPORT_UAPSD
    u_int           isuapsd:1;  /* if this frame needs uapsd handling */
#endif
#ifdef ATH_SUPPORT_TxBF
    u_int           isdelayrpt:1;
#endif

    HAL_PKT_TYPE    atype;      /* Atheros packet type */
    u_int32_t       flags;      /* HAL flags */
    u_int32_t       keyix;      /* key index */
    HAL_KEY_TYPE    keytype;    /* key type */
    u_int16_t       txpower;    /* transmit power */
    u_int16_t       seqno;      /* sequence number */
    u_int16_t       tidno;      /* tid number */

    u_int16_t       frmlen;     /* frame length */
#ifdef USE_LEGACY_HAL
    u_int16_t       hdrlen;     /* header length of this frame */
    int             compression; /* compression scheme */
    u_int8_t        ivlen;      /* iv length for compression */
    u_int8_t        icvlen;     /* icv length for compression */
    u_int8_t        antenna;    /* antenna control */
#endif

    int             min_rate;   /* minimum rate */
    int             mcast_rate; /* multicast rate */
    u_int16_t       nextfraglen; /* next fragment length */

    /* below is set only by ath_dev */
    ath_dev_t       dev;        /* device handle */
    u_int8_t        priv[64];   /* private rate control info */

    OS_DMA_MEM_CONTEXT(dmacontext) /* OS specific DMA context */
#ifdef ATH_SUPPORT_HTC
    u_int8_t nodeindex;
    u_int8_t vapindex;
#ifdef ENCAP_OFFLOAD    
    u_int8_t keyid;
    u_int8_t key_mapping_key;
#endif
#endif
} ieee80211_tx_control_t;
typedef struct {
    u_int   Tries;
    u_int   Rate;
    u_int   PktDuration;
    u_int   ChSel;
    u_int   RateFlags;
    u_int   RateIndex;
    u_int   TxPowerCap;     /* in 1/2 dBm units */
} HAL_11N_RATE_SERIES;
typedef struct {
    int     rateCount;      /* NB: for proper padding */
    u_int8_t    rateCodeToIndex[256];    /* back mapping */
    struct {
        u_int8_t    valid;      /* valid for rate control use */
        u_int8_t    phy;        /* CCK/OFDM/XR */
        u_int32_t   rateKbps;   /* transfer rate in kbs */
        u_int8_t    rateCode;   /* rate for h/w descriptors */
        u_int8_t    shortPreamble;  /* mask for enabling short
                         * preamble in CCK rate code */
        u_int8_t    dot11Rate;  /* value for supported rates
                         * info element of MLME */
        u_int8_t    controlRate;    /* index of next lower basic
                         * rate; used for dur. calcs */
        u_int16_t   lpAckDuration;  /* long preamble ACK duration */
        u_int16_t   spAckDuration;  /* short preamble ACK duration*/
    } info[36];
} HAL_RATE_TABLE;
typedef struct {
    int         rateCount;
    A_UINT8     rateCodeToIndex[RATE_TABLE_SIZE]; /* backward mapping */
    struct {
        A_UINT8   valid: 1,         /* Valid for use in rate control */
                  validUAPSD   : 1; /* Valid for use in rate control for UAPSD operation */
        WLAN_PHY  phy;              /* CCK/OFDM/TURBO/XR */
        A_UINT16  rateKbps;         /* Rate in Kbits per second */
        A_UINT16  userRateKbps;     /* User rate in KBits per second */
        A_UINT8   rateCode;         /* rate that goes into hw descriptors */
        A_UINT8   shortPreamble;    /* Mask for enabling short preamble in rate code for CCK */
        A_UINT8   dot11Rate;        /* Value that goes into supported rates info element of MLME */
        A_UINT8   controlRate;      /* Index of next lower basic rate, used for duration computation */
        A_RSSI    rssiAckValidMin;  /* Rate control related information */
        A_RSSI    rssiAckDeltaMin;  /* Rate control related information */
        A_UINT16  lpAckDuration;    /* long preamble ACK duration */
        A_UINT16  spAckDuration;    /* short preamble ACK duration*/
        A_UINT32  max4msFrameLen;   /* Maximum frame length(bytes) for 4ms tx duration */
        struct {
            A_UINT8  Retries[4];
            A_UINT8  Rates[4];
        } normalSched;
        struct {
            A_UINT8  Retries[4];
            A_UINT8  Rates[4];
        } shortSched;
        struct {
            A_UINT8  Retries[4];
            A_UINT8  Rates[4];
        } probeSched;
        struct {
            A_UINT8  Retries[4];
            A_UINT8  Rates[4];
        } probeShortSched;
        struct {
            A_UINT8  Retries[4];
            A_UINT8  Rates[4];
        } uapsd_normalSched;
        struct {
            A_UINT8  Retries[4];
            A_UINT8  Rates[4];
        } uapsd_shortSched;
    } info[32];
    A_UINT32    probeInterval;        /* interval for ratectrl to probe for
                     other rates */
    A_UINT32    rssiReduceInterval;   /* interval for ratectrl to reduce RSSI */
    A_UINT8     regularToTurboThresh; /* upperbound on regular (11a or 11g)
                     mode's rate before switching to turbo*/
    A_UINT8     turboToRegularThresh; /* lowerbound on turbo mode's rate before
                     switching to regular */
    A_UINT8     pktCountThresh;       /* mode switch recommendation criterion:
                     number of consecutive packets sent at
                     rate beyond the rate threshold */
    A_UINT8     initialRateMax;       /* the initial rateMax value used in
                     rcSibUpdate() */
    A_UINT8     numTurboRates;        /* number of Turbo rates in the rateTable */
    A_UINT8     xrToRegularThresh;    /* threshold to switch to Normal mode */
} RATE_TABLE;
構造関係分析
(1)TAILQ_FOREEACH(bf)&txq->axqu(=2)ds=(struct ahudsec*)bf->bf_desc;(3)TAILQ_FOREEACH(bf)&sc->scraxbuf,bfulist(4)bf=TAILQ_FIRST(&txq->axqufifo[txq->axq tailindex])bf=TAILQ_FIRST(&txq->axq q);(5)ac=TAILQ_FIRST(&txq->axq(6)TAILQ_FOREEACHSAFE(tid)&ac->tiduq,tiduqelem,next tid)(7)bf=TAILQ_FIRST(&tid->buf q);(8)struct ar 9300_txc*ads=AR 9300 TXC(ds);(9)struct ath_atx_.ac*ac=tid->ac;(10)(11)struct ath_node*an=(struct ahunode*)bf->bf_node;
主な過程の分析
ath_reset_start(ath_dev_t dev, HAL_BOOL no_flush, int tx_timeout, int rx_timeout) 
(1)ath_reset_draintxq(struct ath_softc *sc, HAL_BOOL retry_tx, int timeout)--->
1) ath_tx_abortalldma(struct ath_softc *sc)--->
     #define ath_hal_aborttxdma(_ah) \
    ((*(_ah)->ah_abortTxDma)((_ah)))--->
    HAL_BOOL ar9300AbortTxDma(struct ath_hal *ah);
2) ath_reset_drain_txdataq(sc, retry_tx, timeout);

ath_reset_draintxq(struct ath_softc *sc, HAL_BOOL retry_tx, int timeout)--->
1) ath_hal_stoptxdma(sc->sc_ah, sc->sc_bhalq, timeout);
   ar9300StopTxDma(struct ath_hal *ah, u_int q, u_int timeout)
2) ath_reset_drain_txdataq(sc, retry_tx, timeout);
    (1)     
       ath_tx_stopdma(sc, &sc->sc_txq[i], timeout); 
       ar9300StopTxDma(struct ath_hal *ah, u_int q, u_int timeout)
    (2)     
        ath_dump_descriptors(sc);
        dump_txq_desc(sc, &sc->sc_txq[0]);
    dump_txq_desc(sc, &sc->sc_txq[1]);
    dump_txq_desc(sc, &sc->sc_txq[2]);
    dump_txq_desc(sc, &sc->sc_txq[3]);
    dump_txq_desc(sc, sc->sc_cabq);---->
        TAILQ_FOREACH(bf, &txq->axq_q, bf_list)
        ds0 = (struct ath_desc *)bf->bf_desc;
        status = ath_hal_txprocdesc(ah, ds);
        ar9300ProcTxDesc(struct ath_hal *ah, void *txstatus)            
                            ----------   ads = &ahp->ts_ring[ahp->ts_tail];
            ??????bf->bf_daddr == ath_hal_gettxbuf(sc->sc_ah,txq->axq_qnum)
                        dump_desc(sc,bf,txq->axq_qnum);
            ??????ds = (struct ath_desc *)bf->bf_desc;
ath_dump_rx_desc(dev);   ---->
 ath_dump_rx_edma_desc(dev);  ---->
(a)ath_dump_rx_que_desc( struct ath_softc *sc, HAL_RX_QUEUE qtype) ---->
   DPRINTF(sc, ATH_DEBUG_ANY, "%s[%d]: RX[%d]rxedma->rxfifo[%d] %p
",__func__,__LINE__,qtype, i, rxedma->rxfifo[i]); (b)dump_rx_desc(struct ath_softc *sc, int quenum) TAILQ_FOREACH(bf, &sc->sc_rxbuf, bf_list) DPRINTF(sc, ATH_DEBUG_ANY, "%s[%d]: [%d] RX bf 0x%p bf->bf_mpdu %p
",__func__,__LINE__, i++, bf, bf->bf_mpdu); (3) ath_tx_draintxq(struct ath_softc *sc, struct ath_txq *txq, HAL_BOOL retry_tx) (a) bf = TAILQ_FIRST(&txq->axq_fifo[txq->axq_tailindex]); (b) ATH_TXQ_MOVE_HEAD_UNTIL(txq, &bf_head, lastbf, bf_list); (c) ath_txq_drain_pending_buffers(sc, txq); (i) ac = TAILQ_FIRST(&txq->axq_acq) (ii) TAILQ_FOREACH_SAFE(tid, &ac->tid_q, tid_qelem, next_tid) (iii) ath_tid_drain(sc, txq, tid); i. ath_tid_swq_cleanup(sc, txq, tid, &drained_bf_head); ii. tid->seq_next = tid->seq_start; iii. tid->baw_tail = tid->baw_head; iv. ath_complete_drained_tid_buf(sc, &drained_bf_head);
ath_tx_start/tx送信過程分析
(1)__ath_tx_prepare(sc, wbuf, txctl); //txctl  DMA        
(a)an = txctl->an;
(b)txctl->tidno = wbuf_get_tid(wbuf);   
 ……
(2) wbuf_map_sg(sc->sc_osdev, wbuf, OS_GET_DMA_MEM_CONTEXT(txctl, dmacontext),
                    txctl);---》
   __wbuf_map_sg(os_handle, wbuf, context, arg); ---》
(a) wbuf_start_dma(nbf, &sg, 1, arg)
(b) ath_tx_start_dma(nbf, sg, n_sg, arg);
(i)         ath_tx_get_buf(sc, sg, &bf, &bf_head,txctl->qnum, buf_used);
(ii)            bf->bf_frmlen = txctl->frmlen;
(iii)           bf->bf_isdata = txctl->isdata;
(iv)            bf->bf_ismcast = txctl->ismcast;
(v)         bf->bf_useminrate = txctl->use_minrate;
(vi)            bf->bf_isbar = txctl->isbar;
(vii)           bf->bf_ispspoll = txctl->ispspoll;
(viii)          bf->bf_calcairtime = txctl->calcairtime;
(ix)            bf->bf_flags = txctl->flags;
(x)         bf->bf_shpreamble = txctl->shortPreamble;
(xi)            bf->bf_keytype = txctl->keytype;
(xii)           bf->bf_tidno = txctl->tidno;
(xiii)          bf->bf_node = an;
(xiv)           bf->bf_mpdu = wbuf;
(xv)    ds = bf->bf_desc;
(xvi)   OS_COPY_DMA_MEM_CONTEXT(OS_GET_DMA_MEM_CONTEXT(bf, bf_dmacontext), OS_GET_DMA_MEM_CONTEXT(txctl, dmacontext));
(xvii)  
                       ath_hal_set11n_txdesc(ah, ds
                           , bf->bf_frmlen           /* frame length */
                            , txctl->atype            /* Atheros packet type */
                            , MIN(txctl->txpower, 60) /* txpower */
                            , txctl->keyix            /* key cache index */
                            , txctl->keytype          /* key type */
                            , txctl->flags            /* flags */
                );
(xviii)         ath_hal_filltxdesc(ah, ds
                               , (bf->bf_buf_addr)  /* buffer address */
                               , bf->bf_buf_len     /* buffer length */
                               , 0                  /* descriptor id */
                               , bf->bf_qnum        /* QCU number */
                               , txctl->keytype     /* key type */
                               , AH_TRUE            /* first segment */
                        /* last segment */
                       , (n_sg <= sc->sc_num_txmaps) ? AH_TRUE : AH_FALSE 
                               , ds                 /* first descriptor */
                );
(xix)          if (firstbf) { 
(xx)           firstbf->bf_lastfrm = bf;
(xxi)          ath_tx_send_ampdu(sc, txq, tid, &bf_head, txctl);
              // ath_tx_send_normal(sc, txq, tid, &bf_head, txctl);
              ath_tx_addto_baw(sc, tid, bf);
              ath_buf_set_rate(sc, bf);  ---》
                    ath_hal_set11n_ratescenario(ah, ds, lastds,
                                !bf->bf_ispspoll,
                                ctsrate,
                                ctsduration,
                                series, 4, flags, smartAntenna);

ath_tx_send_normal(sc,txq,tid,&bfuhead,txctl)過程分析・・(1)ath_rate_findrate(sc,tid->an,bf->bf preamble,bf->bffuframlen,ATH 11 NuTXMAX TRY,ATHuPROBE,ac,bf->bfracs,&isProbe,AHuFAbraf-,AHuflubraf.
(a)ath_rate_findrate_11 n(sc,an,frame Len,numTries,4,rflags,ac,rcs,isProbe,isretry);(2)bf->bf_nframes=1(3)bf->bf_lastbf=bf->bf_lastfram;/*one single frame*/··ath_tx_send_ampdu(sc,txq,tid,&bfuhead,txctl)プロセス分析