1 /* 2 * Copyright (c) 2008-2011 Atheros Communications Inc. 3 * Copyright (c) 2011 Neratec Solutions AG 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include "hw.h" 19 #include "hw-ops.h" 20 #include "ath9k.h" 21 #include "dfs.h" 22 #include "dfs_debug.h" 23 24 /* internal struct to pass radar data */ 25 struct ath_radar_data { 26 u8 pulse_bw_info; 27 u8 rssi; 28 u8 ext_rssi; 29 u8 pulse_length_ext; 30 u8 pulse_length_pri; 31 }; 32 33 /* convert pulse duration to usecs, considering clock mode */ 34 static u32 dur_to_usecs(struct ath_hw *ah, u32 dur) 35 { 36 const u32 AR93X_NSECS_PER_DUR = 800; 37 const u32 AR93X_NSECS_PER_DUR_FAST = (8000 / 11); 38 u32 nsecs; 39 40 if (IS_CHAN_A_FAST_CLOCK(ah, ah->curchan)) 41 nsecs = dur * AR93X_NSECS_PER_DUR_FAST; 42 else 43 nsecs = dur * AR93X_NSECS_PER_DUR; 44 45 return (nsecs + 500) / 1000; 46 } 47 48 #define PRI_CH_RADAR_FOUND 0x01 49 #define EXT_CH_RADAR_FOUND 0x02 50 static bool 51 ath9k_postprocess_radar_event(struct ath_softc *sc, 52 struct ath_radar_data *ard, 53 struct pulse_event *pe) 54 { 55 u8 rssi; 56 u16 dur; 57 58 ath_dbg(ath9k_hw_common(sc->sc_ah), DFS, 59 "pulse_bw_info=0x%x, pri,ext len/rssi=(%u/%u, %u/%u)\n", 60 ard->pulse_bw_info, 61 ard->pulse_length_pri, ard->rssi, 62 ard->pulse_length_ext, ard->ext_rssi); 63 64 /* 65 * Only the last 2 bits of the BW info are relevant, they indicate 66 * which channel the radar was detected in. 67 */ 68 ard->pulse_bw_info &= 0x03; 69 70 switch (ard->pulse_bw_info) { 71 case PRI_CH_RADAR_FOUND: 72 /* radar in ctrl channel */ 73 dur = ard->pulse_length_pri; 74 DFS_STAT_INC(sc, pri_phy_errors); 75 /* 76 * cannot use ctrl channel RSSI 77 * if extension channel is stronger 78 */ 79 rssi = (ard->ext_rssi >= (ard->rssi + 3)) ? 0 : ard->rssi; 80 break; 81 case EXT_CH_RADAR_FOUND: 82 /* radar in extension channel */ 83 dur = ard->pulse_length_ext; 84 DFS_STAT_INC(sc, ext_phy_errors); 85 /* 86 * cannot use extension channel RSSI 87 * if control channel is stronger 88 */ 89 rssi = (ard->rssi >= (ard->ext_rssi + 12)) ? 0 : ard->ext_rssi; 90 break; 91 case (PRI_CH_RADAR_FOUND | EXT_CH_RADAR_FOUND): 92 /* 93 * Conducted testing, when pulse is on DC, both pri and ext 94 * durations are reported to be same 95 * 96 * Radiated testing, when pulse is on DC, different pri and 97 * ext durations are reported, so take the larger of the two 98 */ 99 if (ard->pulse_length_ext >= ard->pulse_length_pri) 100 dur = ard->pulse_length_ext; 101 else 102 dur = ard->pulse_length_pri; 103 DFS_STAT_INC(sc, dc_phy_errors); 104 105 /* when both are present use stronger one */ 106 rssi = (ard->rssi < ard->ext_rssi) ? ard->ext_rssi : ard->rssi; 107 break; 108 default: 109 /* 110 * Bogus bandwidth info was received in descriptor, 111 * so ignore this PHY error 112 */ 113 DFS_STAT_INC(sc, bwinfo_discards); 114 return false; 115 } 116 117 if (rssi == 0) { 118 DFS_STAT_INC(sc, rssi_discards); 119 return false; 120 } 121 122 /* 123 * TODO: check chirping pulses 124 * checks for chirping are dependent on the DFS regulatory domain 125 * used, which is yet TBD 126 */ 127 128 /* convert duration to usecs */ 129 pe->width = dur_to_usecs(sc->sc_ah, dur); 130 pe->rssi = rssi; 131 132 DFS_STAT_INC(sc, pulses_detected); 133 return true; 134 } 135 #undef PRI_CH_RADAR_FOUND 136 #undef EXT_CH_RADAR_FOUND 137 138 /* 139 * DFS: check PHY-error for radar pulse and feed the detector 140 */ 141 void ath9k_dfs_process_phyerr(struct ath_softc *sc, void *data, 142 struct ath_rx_status *rs, u64 mactime) 143 { 144 struct ath_radar_data ard; 145 u16 datalen; 146 char *vdata_end; 147 struct pulse_event pe; 148 struct ath_hw *ah = sc->sc_ah; 149 struct ath_common *common = ath9k_hw_common(ah); 150 151 DFS_STAT_INC(sc, pulses_total); 152 if ((rs->rs_phyerr != ATH9K_PHYERR_RADAR) && 153 (rs->rs_phyerr != ATH9K_PHYERR_FALSE_RADAR_EXT)) { 154 ath_dbg(common, DFS, 155 "Error: rs_phyer=0x%x not a radar error\n", 156 rs->rs_phyerr); 157 DFS_STAT_INC(sc, pulses_no_dfs); 158 return; 159 } 160 161 datalen = rs->rs_datalen; 162 if (datalen == 0) { 163 DFS_STAT_INC(sc, datalen_discards); 164 return; 165 } 166 167 ard.rssi = rs->rs_rssi_ctl0; 168 ard.ext_rssi = rs->rs_rssi_ext0; 169 170 /* 171 * hardware stores this as 8 bit signed value. 172 * we will cap it at 0 if it is a negative number 173 */ 174 if (ard.rssi & 0x80) 175 ard.rssi = 0; 176 if (ard.ext_rssi & 0x80) 177 ard.ext_rssi = 0; 178 179 vdata_end = (char *)data + datalen; 180 ard.pulse_bw_info = vdata_end[-1]; 181 ard.pulse_length_ext = vdata_end[-2]; 182 ard.pulse_length_pri = vdata_end[-3]; 183 pe.freq = ah->curchan->channel; 184 pe.ts = mactime; 185 if (ath9k_postprocess_radar_event(sc, &ard, &pe)) { 186 struct dfs_pattern_detector *pd = sc->dfs_detector; 187 static u64 last_ts; 188 ath_dbg(common, DFS, 189 "ath9k_dfs_process_phyerr: channel=%d, ts=%llu, " 190 "width=%d, rssi=%d, delta_ts=%llu\n", 191 pe.freq, pe.ts, pe.width, pe.rssi, pe.ts-last_ts); 192 last_ts = pe.ts; 193 DFS_STAT_INC(sc, pulses_processed); 194 if (pd != NULL && pd->add_pulse(pd, &pe)) { 195 DFS_STAT_INC(sc, radar_detected); 196 /* 197 * TODO: forward radar event to DFS management layer 198 */ 199 } 200 } 201 } 202