[ath_hal_ar9300] Add some comments around the AR9300 ANI code.

I'm refamiliarising myself with the behaviour of the ANI code and I thought
I'd drop some comments to remind myself.
This commit is contained in:
Adrian Chadd 2019-03-19 00:07:12 +00:00
parent eccf47f57a
commit c788d9b010

View File

@ -1217,6 +1217,7 @@ ar9300_ani_ar_poll(struct ath_hal *ah, const HAL_NODE_STATS *stats,
cck_phy_err_cnt = OS_REG_READ(ah, AR_PHY_ERR_2);
/* Populate HAL_ANISTATS */
/* XXX TODO: are these correct? */
if (ani_stats) {
ani_stats->cckphyerr_cnt =
cck_phy_err_cnt - ani_state->cck_phy_err_count;
@ -1257,18 +1258,32 @@ ar9300_ani_ar_poll(struct ath_hal *ah, const HAL_NODE_STATS *stats,
return;
}
/*
* Calculate the OFDM/CCK phy error rate over the listen time interval.
* This is used in subsequent math to see if the OFDM/CCK phy error rate
* is above or below the threshold checks.
*/
ofdm_phy_err_rate =
ani_state->ofdm_phy_err_count * 1000 / ani_state->listen_time;
cck_phy_err_rate =
ani_state->cck_phy_err_count * 1000 / ani_state->listen_time;
HALDEBUG(ah, HAL_DEBUG_ANI,
"%s: listen_time=%d OFDM:%d errs=%d/s CCK:%d errs=%d/s ofdm_turn=%d\n",
"%s: listen_time=%d (total: %d) OFDM:%d errs=%d/s CCK:%d errs=%d/s ofdm_turn=%d\n",
__func__, listen_time,
ani_state->listen_time,
ani_state->ofdm_noise_immunity_level, ofdm_phy_err_rate,
ani_state->cck_noise_immunity_level, cck_phy_err_rate,
ani_state->ofdms_turn);
/*
* Check for temporary noise spurs. This is intended to be used by
* rate control to check if we should try higher packet rates or not.
* If the noise period is short enough then we shouldn't avoid trying
* higher rates but if the noise is high/sustained then it's likely
* not a great idea to try the higher MCS rates.
*/
if (ani_state->listen_time >= HAL_NOISE_DETECT_PERIOD) {
old_phy_noise_spur = ani_state->phy_noise_spur;
if (ofdm_phy_err_rate <= ani_state->ofdm_trig_low &&
@ -1281,7 +1296,7 @@ ar9300_ani_ar_poll(struct ath_hal *ah, const HAL_NODE_STATS *stats,
}
if (old_phy_noise_spur != ani_state->phy_noise_spur) {
HALDEBUG(ah, HAL_DEBUG_ANI,
"%s: enviroment change from %d to %d\n",
"%s: environment change from %d to %d\n",
__func__, old_phy_noise_spur, ani_state->phy_noise_spur);
}
}
@ -1304,6 +1319,10 @@ ar9300_ani_ar_poll(struct ath_hal *ah, const HAL_NODE_STATS *stats,
ar9300_ani_lower_immunity(ah);
ani_state->ofdms_turn = !ani_state->ofdms_turn;
}
/*
* Force an ANI restart regardless of whether the lower immunity
* level was met.
*/
HALDEBUG(ah, HAL_DEBUG_ANI,
"%s: 1 listen_time=%d ofdm=%d/s cck=%d/s - "
"calling ar9300_ani_restart\n",
@ -1337,6 +1356,13 @@ ar9300_ani_ar_poll(struct ath_hal *ah, const HAL_NODE_STATS *stats,
ani_state->ofdms_turn = AH_TRUE;
}
}
/*
* Note that currently this poll function doesn't reset the listen
* time after it accumulates a second worth of error samples.
* It will continue to accumulate samples until a counter overflows,
* or a raise threshold is met, or 5 seconds passes.
*/
}
/*