wifi: mt76: Fix EHT NSS radiotap reporting.

Wireshark and iwlwifi use zero-based NSS reporting, adjust
mt76 to do the same.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Link: https://patch.msgid.link/20240909211238.3237111-2-greearb@candelatech.com
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac3_mac.c b/drivers/net/wireless/mediatek/mt76/mt76_connac3_mac.c
index 92ad1ecf6c9d4e2f78fe37924b90fb4528f625f0..2d300948308d92e35c7a9ee16986e21a617ce0be 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac3_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac3_mac.c
@@ -231,7 +231,8 @@ void mt76_connac3_mac_decode_eht_radiotap(struct sk_buff *skb, __le32 *rxv,
                EHT_PREP(DATA0_PE_DISAMBIGUITY_OM, PE_DISAMBIG, rxv[5]) |
                EHT_PREP(DATA0_LDPC_EXTRA_SYM_OM, LDPC_EXT_SYM, rxv[4]);
 
-       eht->data[7] |= le32_encode_bits(status->nss, IEEE80211_RADIOTAP_EHT_DATA7_NSS_S);
+       /* iwlwifi and wireshark expect radiotap to report zero-based NSS, so subtract 1. */
+       eht->data[7] |= le32_encode_bits(status->nss - 1, IEEE80211_RADIOTAP_EHT_DATA7_NSS_S);
 
        eht->user_info[0] |=
                EHT_BITS(USER_INFO_MCS_KNOWN) |
@@ -240,7 +241,7 @@ void mt76_connac3_mac_decode_eht_radiotap(struct sk_buff *skb, __le32 *rxv,
                EHT_BITS(USER_INFO_BEAMFORMING_KNOWN_O) |
                EHT_BITS(USER_INFO_DATA_FOR_USER) |
                le32_encode_bits(status->rate_idx, IEEE80211_RADIOTAP_EHT_USER_INFO_MCS) |
-               le32_encode_bits(status->nss, IEEE80211_RADIOTAP_EHT_USER_INFO_NSS_O);
+               le32_encode_bits(status->nss - 1, IEEE80211_RADIOTAP_EHT_USER_INFO_NSS_O);
 
        if (le32_to_cpu(rxv[0]) & MT_PRXV_TXBF)
                eht->user_info[0] |= EHT_BITS(USER_INFO_BEAMFORMING_O);