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[iwm] fix up RSSI calculations for both scan results and normal RX operations.

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* hard code a noise floor of -96 for now. The noise floor update code returns
  some "interesting" values that I can't map to anything useful right now.
* Ensure a default noise floor is set - otherwise the initial scan results
  have a noise floor of '0'.
* Fix up the RSSI calculation to be correctly relative to the noise floor.
  The RSSI routines return an absolute value in dBm - so fix this up.
* Cap RSSI values appropriately.
* Ensure we pass in a 1/2 dB unit value in to net80211.

Tested:

* Intel 7260, STA mode

iwm0: <Intel Dual Band Wireless AC 7260> mem 0xf1400000-0xf1401fff irq 17 at device 0.0 on pci2
iwm0: hw rev 0x140, fw ver 16.242414.0, address xx:xx:xx:xx:xx:xx
This commit is contained in:
adrian 2016-09-18 05:07:18 +00:00
parent 642ffb1e77
commit d401a8ed6e
1 changed files with 36 additions and 6 deletions

42
sys/dev/iwm/if_iwm.c

@ -312,7 +312,8 @@ static int iwm_mvm_get_signal_strength(struct iwm_softc *,
static void iwm_mvm_rx_rx_phy_cmd(struct iwm_softc *,
struct iwm_rx_packet *,
struct iwm_rx_data *);
static int iwm_get_noise(const struct iwm_mvm_statistics_rx_non_phy *);
static int iwm_get_noise(struct iwm_softc *sc,
const struct iwm_mvm_statistics_rx_non_phy *);
static void iwm_mvm_rx_rx_mpdu(struct iwm_softc *, struct iwm_rx_packet *,
struct iwm_rx_data *);
static int iwm_mvm_rx_tx_cmd_single(struct iwm_softc *,
@ -2871,21 +2872,34 @@ iwm_mvm_rx_rx_phy_cmd(struct iwm_softc *sc,
* Retrieve the average noise (in dBm) among receivers.
*/
static int
iwm_get_noise(const struct iwm_mvm_statistics_rx_non_phy *stats)
iwm_get_noise(struct iwm_softc *sc,
const struct iwm_mvm_statistics_rx_non_phy *stats)
{
int i, total, nbant, noise;
total = nbant = noise = 0;
for (i = 0; i < 3; i++) {
noise = le32toh(stats->beacon_silence_rssi[i]) & 0xff;
IWM_DPRINTF(sc, IWM_DEBUG_RECV, "%s: i=%d, noise=%d\n",
__func__,
i,
noise);
if (noise) {
total += noise;
nbant++;
}
}
IWM_DPRINTF(sc, IWM_DEBUG_RECV, "%s: nbant=%d, total=%d\n",
__func__, nbant, total);
#if 0
/* There should be at least one antenna but check anyway. */
return (nbant == 0) ? -127 : (total / nbant) - 107;
#else
/* For now, just hard-code it to -96 to be safe */
return (-96);
#endif
}
/*
@ -2940,8 +2954,15 @@ iwm_mvm_rx_rx_mpdu(struct iwm_softc *sc,
} else {
rssi = iwm_mvm_calc_rssi(sc, phy_info);
}
rssi = (0 - IWM_MIN_DBM) + rssi; /* normalize */
rssi = MIN(rssi, sc->sc_max_rssi); /* clip to max. 100% */
/* Note: RSSI is absolute (ie a -ve value) */
if (rssi < IWM_MIN_DBM)
rssi = IWM_MIN_DBM;
else if (rssi > IWM_MAX_DBM)
rssi = IWM_MAX_DBM;
/* Map it to relative value */
rssi = rssi - sc->sc_noise;
/* replenish ring for the buffer we're going to feed to the sharks */
if (iwm_rx_addbuf(sc, IWM_RBUF_SIZE, sc->rxq.cur) != 0) {
@ -2950,6 +2971,9 @@ iwm_mvm_rx_rx_mpdu(struct iwm_softc *sc,
return;
}
IWM_DPRINTF(sc, IWM_DEBUG_RECV,
"%s: rssi=%d, noise=%d\n", __func__, rssi, sc->sc_noise);
ni = ieee80211_find_rxnode(ic, (struct ieee80211_frame_min *)wh);
IWM_DPRINTF(sc, IWM_DEBUG_RECV,
@ -2970,7 +2994,9 @@ iwm_mvm_rx_rx_mpdu(struct iwm_softc *sc,
} else {
rxs.c_freq = ieee80211_ieee2mhz(rxs.c_ieee, IEEE80211_CHAN_5GHZ);
}
rxs.rssi = rssi - sc->sc_noise;
/* rssi is in 1/2db units */
rxs.rssi = rssi * 2;
rxs.nf = sc->sc_noise;
if (ieee80211_radiotap_active_vap(vap)) {
@ -5172,7 +5198,7 @@ iwm_notif_intr(struct iwm_softc *sc)
struct iwm_notif_statistics *stats;
SYNC_RESP_STRUCT(stats, pkt);
memcpy(&sc->sc_stats, stats, sizeof(sc->sc_stats));
sc->sc_noise = iwm_get_noise(&stats->rx.general);
sc->sc_noise = iwm_get_noise(sc, &stats->rx.general);
break; }
case IWM_NVM_ACCESS_CMD:
@ -5823,8 +5849,12 @@ iwm_attach(device_t dev)
sc->sc_phyctxt[i].channel = NULL;
}
/* Default noise floor */
sc->sc_noise = -96;
/* Max RSSI */
sc->sc_max_rssi = IWM_MAX_DBM - IWM_MIN_DBM;
sc->sc_preinit_hook.ich_func = iwm_preinit;
sc->sc_preinit_hook.ich_arg = sc;
if (config_intrhook_establish(&sc->sc_preinit_hook) != 0) {