diff options
Diffstat (limited to 'drivers/net/wireless/ath/ath9k/dfs.c')
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/dfs.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath9k/dfs.c b/drivers/net/wireless/ath/ath9k/dfs.c new file mode 100644 index 00000000000..726271c7c33 --- /dev/null +++ b/drivers/net/wireless/ath/ath9k/dfs.c @@ -0,0 +1,193 @@ +/* + * Copyright (c) 2008-2011 Atheros Communications Inc. + * Copyright (c) 2011 Neratec Solutions AG + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "hw.h" +#include "hw-ops.h" +#include "ath9k.h" +#include "dfs.h" +#include "dfs_debug.h" + +/* internal struct to pass radar data */ +struct ath_radar_data { + u8 pulse_bw_info; + u8 rssi; + u8 ext_rssi; + u8 pulse_length_ext; + u8 pulse_length_pri; +}; + +/* convert pulse duration to usecs, considering clock mode */ +static u32 dur_to_usecs(struct ath_hw *ah, u32 dur) +{ + const u32 AR93X_NSECS_PER_DUR = 800; + const u32 AR93X_NSECS_PER_DUR_FAST = (8000 / 11); + u32 nsecs; + + if (IS_CHAN_A_FAST_CLOCK(ah, ah->curchan)) + nsecs = dur * AR93X_NSECS_PER_DUR_FAST; + else + nsecs = dur * AR93X_NSECS_PER_DUR; + + return (nsecs + 500) / 1000; +} + +#define PRI_CH_RADAR_FOUND 0x01 +#define EXT_CH_RADAR_FOUND 0x02 +static bool +ath9k_postprocess_radar_event(struct ath_softc *sc, + struct ath_radar_data *ard, + struct pulse_event *pe) +{ + u8 rssi; + u16 dur; + + /* + * Only the last 2 bits of the BW info are relevant, they indicate + * which channel the radar was detected in. + */ + ard->pulse_bw_info &= 0x03; + + switch (ard->pulse_bw_info) { + case PRI_CH_RADAR_FOUND: + /* radar in ctrl channel */ + dur = ard->pulse_length_pri; + DFS_STAT_INC(sc, pri_phy_errors); + /* + * cannot use ctrl channel RSSI + * if extension channel is stronger + */ + rssi = (ard->ext_rssi >= (ard->rssi + 3)) ? 0 : ard->rssi; + break; + case EXT_CH_RADAR_FOUND: + /* radar in extension channel */ + dur = ard->pulse_length_ext; + DFS_STAT_INC(sc, ext_phy_errors); + /* + * cannot use extension channel RSSI + * if control channel is stronger + */ + rssi = (ard->rssi >= (ard->ext_rssi + 12)) ? 0 : ard->ext_rssi; + break; + case (PRI_CH_RADAR_FOUND | EXT_CH_RADAR_FOUND): + /* + * Conducted testing, when pulse is on DC, both pri and ext + * durations are reported to be same + * + * Radiated testing, when pulse is on DC, different pri and + * ext durations are reported, so take the larger of the two + */ + if (ard->pulse_length_ext >= ard->pulse_length_pri) + dur = ard->pulse_length_ext; + else + dur = ard->pulse_length_pri; + DFS_STAT_INC(sc, dc_phy_errors); + + /* when both are present use stronger one */ + rssi = (ard->rssi < ard->ext_rssi) ? ard->ext_rssi : ard->rssi; + break; + default: + /* + * Bogus bandwidth info was received in descriptor, + * so ignore this PHY error + */ + DFS_STAT_INC(sc, bwinfo_discards); + return false; + } + + if (rssi == 0) { + DFS_STAT_INC(sc, rssi_discards); + return false; + } + + /* + * TODO: check chirping pulses + * checks for chirping are dependent on the DFS regulatory domain + * used, which is yet TBD + */ + + /* convert duration to usecs */ + pe->width = dur_to_usecs(sc->sc_ah, dur); + pe->rssi = rssi; + + DFS_STAT_INC(sc, pulses_detected); + return true; +} +#undef PRI_CH_RADAR_FOUND +#undef EXT_CH_RADAR_FOUND + +/* + * DFS: check PHY-error for radar pulse and feed the detector + */ +void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data, + struct ath_rx_status *rs, u64 mactime) +{ + struct ath_radar_data ard; + u16 datalen; + char *vdata_end; + struct pulse_event pe; + struct ath_hw *ah = sc->sc_ah; + struct ath_common *common = ath9k_hw_common(ah); + + DFS_STAT_INC(sc, pulses_total); + if ((rs->rs_phyerr != ATH9K_PHYERR_RADAR) && + (rs->rs_phyerr != ATH9K_PHYERR_FALSE_RADAR_EXT)) { + ath_dbg(common, DFS, + "Error: rs_phyer=0x%x not a radar error\n", + rs->rs_phyerr); + DFS_STAT_INC(sc, pulses_no_dfs); + return; + } + + datalen = rs->rs_datalen; + if (datalen == 0) { + DFS_STAT_INC(sc, datalen_discards); + return; + } + + ard.rssi = rs->rs_rssi_ctl[0]; + ard.ext_rssi = rs->rs_rssi_ext[0]; + + /* + * hardware stores this as 8 bit signed value. + * we will cap it at 0 if it is a negative number + */ + if (ard.rssi & 0x80) + ard.rssi = 0; + if (ard.ext_rssi & 0x80) + ard.ext_rssi = 0; + + vdata_end = (char *)data + datalen; + ard.pulse_bw_info = vdata_end[-1]; + ard.pulse_length_ext = vdata_end[-2]; + ard.pulse_length_pri = vdata_end[-3]; + pe.freq = ah->curchan->channel; + pe.ts = mactime; + if (ath9k_postprocess_radar_event(sc, &ard, &pe)) { + struct dfs_pattern_detector *pd = sc->dfs_detector; + ath_dbg(common, DFS, + "ath9k_dfs_process_phyerr: channel=%d, ts=%llu, " + "width=%d, rssi=%d, delta_ts=%llu\n", + pe.freq, pe.ts, pe.width, pe.rssi, + pe.ts - sc->dfs_prev_pulse_ts); + sc->dfs_prev_pulse_ts = pe.ts; + DFS_STAT_INC(sc, pulses_processed); + if (pd != NULL && pd->add_pulse(pd, &pe)) { + DFS_STAT_INC(sc, radar_detected); + ieee80211_radar_detected(sc->hw); + } + } +} |