2022-03-04 21:25:17

by Ben Greear

[permalink] [raw]
Subject: [PATCH] iwlwifi: Fix per-chain rssi averaging for 1nss frames.

From: Ben Greear <[email protected]>

Averaging in the weak secondary chain for a single-spatial-stream packet
causes the per-chain averages to look abnormally weak. So, move calculation
of nss above where the rssi is calculated, and then use the nss inside the
rssi-calculation to ignore the weak spatial stream for 1nss frames.

Signed-off-by: Ben Greear <[email protected]>
---

NOTE: This on top of the two other related patches I sent recently.

drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c | 102 ++++++++++--------
1 file changed, 58 insertions(+), 44 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
index 489f8a843f82..ac555ae7c180 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
@@ -285,12 +285,26 @@ static void iwl_mvm_get_signal_strength(struct iwl_mvm *mvm,
u32 rate_flags = rate_n_flags;
struct iwl_mvm_sta *mvmsta = NULL;

+ rx_status->chains =
+ (rate_flags & RATE_MCS_ANT_AB_MSK) >> RATE_MCS_ANT_POS;
+
if (sta && !(is_beacon && !my_beacon)) {
mvmsta = iwl_mvm_sta_from_mac80211(sta);
- if (energy_a)
- ewma_signal_add(&mvmsta->rx_avg_chain_signal[0], energy_a);
- if (energy_b)
- ewma_signal_add(&mvmsta->rx_avg_chain_signal[1], energy_b);
+ /* In cases of OFDM encodings (and maybe other cases), energy is
+ * reported for each chain, but we do not want to average the weak
+ * chain since it will average in a false weak reading.
+ */
+ if (rx_status->nss >= 2) {
+ if (energy_a)
+ ewma_signal_add(&mvmsta->rx_avg_chain_signal[0], energy_a);
+ if (energy_b)
+ ewma_signal_add(&mvmsta->rx_avg_chain_signal[1], energy_b);
+ } else {
+ if (energy_a && (energy_a >= energy_b))
+ ewma_signal_add(&mvmsta->rx_avg_chain_signal[0], energy_a);
+ else if (energy_b)
+ ewma_signal_add(&mvmsta->rx_avg_chain_signal[1], energy_b);
+ }
}

energy_a = energy_a ? -energy_a : S8_MIN;
@@ -303,8 +317,6 @@ static void iwl_mvm_get_signal_strength(struct iwl_mvm *mvm,
energy_a, energy_b, max_energy);

rx_status->signal = max_energy;
- rx_status->chains =
- (rate_flags & RATE_MCS_ANT_AB_MSK) >> RATE_MCS_ANT_POS;
rx_status->chain_signal[0] = energy_a;
rx_status->chain_signal[1] = energy_b;

@@ -1906,6 +1918,46 @@ void iwl_mvm_rx_mpdu_mq(struct iwl_mvm *mvm, struct napi_struct *napi,
my_beacon = true;
}

+ is_sgi = format == RATE_MCS_HE_MSK ?
+ iwl_he_is_sgi(rate_n_flags) :
+ rate_n_flags & RATE_MCS_SGI_MSK;
+
+ if (!(format == RATE_MCS_CCK_MSK) && is_sgi)
+ rx_status->enc_flags |= RX_ENC_FLAG_SHORT_GI;
+ if (rate_n_flags & RATE_MCS_LDPC_MSK)
+ rx_status->enc_flags |= RX_ENC_FLAG_LDPC;
+ if (format == RATE_MCS_HT_MSK) {
+ u8 stbc = (rate_n_flags & RATE_MCS_STBC_MSK) >>
+ RATE_MCS_STBC_POS;
+ rx_status->encoding = RX_ENC_HT;
+ rx_status->rate_idx = RATE_HT_MCS_INDEX(rate_n_flags);
+ rx_status->nss = rx_status->rate_idx / 8 + 1;
+ rx_status->enc_flags |= stbc << RX_ENC_FLAG_STBC_SHIFT;
+ } else if (format == RATE_MCS_VHT_MSK) {
+ u8 stbc = (rate_n_flags & RATE_MCS_STBC_MSK) >>
+ RATE_MCS_STBC_POS;
+ rx_status->nss =
+ ((rate_n_flags & RATE_MCS_NSS_MSK) >>
+ RATE_MCS_NSS_POS) + 1;
+ rx_status->rate_idx = rate_n_flags & RATE_MCS_CODE_MSK;
+ rx_status->encoding = RX_ENC_VHT;
+ rx_status->enc_flags |= stbc << RX_ENC_FLAG_STBC_SHIFT;
+ if (rate_n_flags & RATE_MCS_BF_MSK)
+ rx_status->enc_flags |= RX_ENC_FLAG_BF;
+ } else if (!(format == RATE_MCS_HE_MSK)) {
+ int rate = iwl_mvm_legacy_hw_idx_to_mac80211_idx(rate_n_flags,
+ rx_status->band);
+
+ if (WARN(rate < 0 || rate > 0xFF,
+ "Invalid rate flags 0x%x, band %d,\n",
+ rate_n_flags, rx_status->band)) {
+ kfree_skb(skb);
+ goto out;
+ }
+ rx_status->rate_idx = rate;
+ rx_status->nss = 1;
+ }
+
iwl_mvm_get_signal_strength(mvm, rx_status, rate_n_flags, energy_a,
energy_b, sta, is_beacon, my_beacon);

@@ -2006,44 +2058,6 @@ void iwl_mvm_rx_mpdu_mq(struct iwl_mvm *mvm, struct napi_struct *napi,
}
}

- is_sgi = format == RATE_MCS_HE_MSK ?
- iwl_he_is_sgi(rate_n_flags) :
- rate_n_flags & RATE_MCS_SGI_MSK;
-
- if (!(format == RATE_MCS_CCK_MSK) && is_sgi)
- rx_status->enc_flags |= RX_ENC_FLAG_SHORT_GI;
- if (rate_n_flags & RATE_MCS_LDPC_MSK)
- rx_status->enc_flags |= RX_ENC_FLAG_LDPC;
- if (format == RATE_MCS_HT_MSK) {
- u8 stbc = (rate_n_flags & RATE_MCS_STBC_MSK) >>
- RATE_MCS_STBC_POS;
- rx_status->encoding = RX_ENC_HT;
- rx_status->rate_idx = RATE_HT_MCS_INDEX(rate_n_flags);
- rx_status->enc_flags |= stbc << RX_ENC_FLAG_STBC_SHIFT;
- } else if (format == RATE_MCS_VHT_MSK) {
- u8 stbc = (rate_n_flags & RATE_MCS_STBC_MSK) >>
- RATE_MCS_STBC_POS;
- rx_status->nss =
- ((rate_n_flags & RATE_MCS_NSS_MSK) >>
- RATE_MCS_NSS_POS) + 1;
- rx_status->rate_idx = rate_n_flags & RATE_MCS_CODE_MSK;
- rx_status->encoding = RX_ENC_VHT;
- rx_status->enc_flags |= stbc << RX_ENC_FLAG_STBC_SHIFT;
- if (rate_n_flags & RATE_MCS_BF_MSK)
- rx_status->enc_flags |= RX_ENC_FLAG_BF;
- } else if (!(format == RATE_MCS_HE_MSK)) {
- int rate = iwl_mvm_legacy_hw_idx_to_mac80211_idx(rate_n_flags,
- rx_status->band);
-
- if (WARN(rate < 0 || rate > 0xFF,
- "Invalid rate flags 0x%x, band %d,\n",
- rate_n_flags, rx_status->band)) {
- kfree_skb(skb);
- goto out;
- }
- rx_status->rate_idx = rate;
- }
-
/* management stuff on default queue */
if (!queue) {
if (unlikely((ieee80211_is_beacon(hdr->frame_control) ||
--
2.20.1