by Sujith Manoharan

[permalink] [raw]

Subject: [PATCH 5/9] ath9k_hw: remove the old ANI implementation

Felix Fietkau wrote:
> It was found to be buggy on a variety of chipsets from AR913x to AR928x.
> The new version (which was introduced along with AR93xx support) is more
> reliable in preventing connectivity dropouts and also fixes MIB interrupt
> storm issues.

What bugs exactly ? Can you elaborate which cases show improvement ?
OFDM weak signal detection ?
CCK weak signal detection ?
Noise immunity ?
Firstep_Level ?

MIB interrupt storms will not be seen because they aren't used at all.

False positives are an issue with ANI and has this been studied with the
move to the new algorithm ?

The new ANI algorithm is designed to take advantage of the HW improvements
in AR300 and above. Has it been verified that the older HW generation can actually
conform to the requirements of the new algorithm ?

If there are bugs or regressions in the existing code in ath9k, we can surely
fix them. But IMHO, saying 'general stability is improved' is not really a
justification for code extermination. Why can't we opt for a more evolutionary
approach ?

Sujith

2012-06-15 13:25:38

by Felix Fietkau

[permalink] [raw]

Subject: [PATCH 9/9] ath9k_hw: clean up ANI OFDM trigger handling

Adjust ah->config.ofdm_trig_{high,low} when setting noise immunity values
to simplify threshold checks in ath9k_hw_ani_monitor

Signed-off-by: Felix Fietkau <[email protected]>
---
drivers/net/wireless/ath/ath9k/ani.c | 23 ++++++++++-------------
1 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ani.c b/drivers/net/wireless/ath/ath9k/ani.c
index 6ee0875..a90aa0b 100644
--- a/drivers/net/wireless/ath/ath9k/ani.c
+++ b/drivers/net/wireless/ath/ath9k/ani.c
@@ -179,6 +179,14 @@ static void ath9k_hw_set_ofdm_nil(struct ath_hw *ah, u8 immunityLevel)
ath9k_hw_ani_control(ah,
ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION,
entry_ofdm->ofdm_weak_signal_on);
+
+ if (aniState->ofdmNoiseImmunityLevel >= ATH9K_ANI_OFDM_DEF_LEVEL) {
+ ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH;
+ ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW_ABOVE_INI;
+ } else {
+ ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH_BELOW_INI;
+ ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW;
+ }
}

static void ath9k_hw_ani_ofdm_err_trigger(struct ath_hw *ah)
@@ -428,21 +436,10 @@ void ath9k_hw_ani_monitor(struct ath_hw *ah, struct ath9k_channel *chan)

if (aniState->listenTime > ah->aniperiod) {
if (cckPhyErrRate < ah->config.cck_trig_low &&
- ((ofdmPhyErrRate < ah->config.ofdm_trig_low &&
- aniState->ofdmNoiseImmunityLevel <
- ATH9K_ANI_OFDM_DEF_LEVEL) ||
- (ofdmPhyErrRate < ATH9K_ANI_OFDM_TRIG_LOW_ABOVE_INI &&
- aniState->ofdmNoiseImmunityLevel >=
- ATH9K_ANI_OFDM_DEF_LEVEL))) {
+ ofdmPhyErrRate < ah->config.ofdm_trig_low) {
ath9k_hw_ani_lower_immunity(ah);
aniState->ofdmsTurn = !aniState->ofdmsTurn;
- } else if ((ofdmPhyErrRate > ah->config.ofdm_trig_high &&
- aniState->ofdmNoiseImmunityLevel >=
- ATH9K_ANI_OFDM_DEF_LEVEL) ||
- (ofdmPhyErrRate >
- ATH9K_ANI_OFDM_TRIG_HIGH_BELOW_INI &&
- aniState->ofdmNoiseImmunityLevel <
- ATH9K_ANI_OFDM_DEF_LEVEL)) {
+ } else if (ofdmPhyErrRate > ah->config.ofdm_trig_high) {
ath9k_hw_ani_ofdm_err_trigger(ah);
aniState->ofdmsTurn = false;
} else if (cckPhyErrRate > ah->config.cck_trig_high) {
--
1.7.3.2