MadWifi理解筆記091124

 

關於在MadWifi速率控制算法中獲得RSSI

 

以SampleRate算法代碼爲例：

 

in function:  static void ath_rate_tx_complete(struct ath_softc *sc,  struct ath_node *an, const struct ath_buf *bf)

 

const struct ath_tx_status *ts = &bf->bf_dsstatus.ds_txstat;

 

Then the RSSI is : ts->ts_rssi.

 

 

---

 

 

 

struct ath_buf { /* FFXXX: convert both list types to TAILQ to save a field? */ STAILQ_ENTRY(ath_buf) bf_list; #ifdef ATH_SUPERG_FF TAILQ_ENTRY(ath_buf) bf_stagelist; /* fast-frame staging list */ #endif struct ath_desc *bf_desc; /* virtual addr of desc */ struct ath_desc_status bf_dsstatus; /* tx/rx descriptor status */ dma_addr_t bf_daddr; /* physical addr of desc */ struct sk_buff *bf_skb; /* skbuff for buf */ dma_addr_t bf_skbaddr; /* physical addr of skb data - always used by one desc */ u_int32_t bf_status; /* status flags */ u_int16_t bf_flags; /* tx descriptor flags */ u_int64_t bf_tsf; int16_t bf_channoise; #ifdef ATH_SUPERG_FF /* XXX: combine this with bf_skbaddr if it ever changes to accommodate * multiple segments. */ u_int16_t bf_numdescff; /* number of descs used for FF (these are extra) */ u_int32_t bf_queueage; /* "age" of txq when this buffer placed on stageq */ dma_addr_t bf_skbaddrff[ATH_TXDESC - 1]; /* extra addrs for FF */ #endif int bf_taken_at_line; /* XXX: Want full alloc backtrace */ const char *bf_taken_at_func; };

 

 

struct ath_desc_status { union { struct ath_tx_status tx;/* xmit status */ struct ath_rx_status rx;/* recv status */ } ds_us; }; #define ds_txstat ds_us.tx #define ds_rxstat ds_us.rx

 

struct ath_tx_status { u_int16_t ts_seqnum; /* h/w assigned sequence number */ u_int16_t ts_tstamp; /* h/w assigned timestamp */ u_int8_t ts_status; /* frame status, 0 => xmit ok */ u_int8_t ts_rate; /* h/w transmit rate index */ #define HAL_TXSTAT_ALTRATE 0x80 /* alternate xmit rate used */ int8_t ts_rssi; /* tx ack RSSI */ u_int8_t ts_shortretry; /* # short retries */ u_int8_t ts_longretry; /* # long retries */ u_int8_t ts_virtcol; /* virtual collision count */ u_int8_t ts_antenna; /* antenna information */ u_int8_t ts_finaltsi; /* final transmit series index */ #ifdef AH_SUPPORT_AR5416 /* 802.11n status */ u_int8_t ts_flags; /* misc flags */ int8_t ts_rssi_ctl[3]; /* tx ack RSSI [ctl, chain 0-2] */ int8_t ts_rssi_ext[3]; /* tx ack RSSI [ext, chain 0-2] */ /* #define ts_rssi ts_rssi_combined */ u_int32_t ts_ba_low; /* blockack bitmap low */ u_int32_t ts_ba_high; /* blockack bitmap high */ u_int32_t ts_evm0; /* evm bytes */ u_int32_t ts_evm1; u_int32_t ts_evm2; #endif /* AH_SUPPORT_AR5416 */ };