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/*
* 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);
}
}
}
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