diff options
Diffstat (limited to 'drivers/net/wireless/iwlwifi/iwl-rx.c')
| -rw-r--r-- | drivers/net/wireless/iwlwifi/iwl-rx.c | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c index 1690b49bb136..f3f3efe38ce2 100644 --- a/drivers/net/wireless/iwlwifi/iwl-rx.c +++ b/drivers/net/wireless/iwlwifi/iwl-rx.c @@ -902,6 +902,47 @@ static u32 iwl_translate_rx_status(struct iwl_priv *priv, u32 decrypt_in) return decrypt_out; } +/* Calc max signal level (dBm) among 3 possible receivers */ +static int iwlagn_calc_rssi(struct iwl_priv *priv, + struct iwl_rx_phy_res *rx_resp) +{ + /* data from PHY/DSP regarding signal strength, etc., + * contents are always there, not configurable by host + */ + struct iwlagn_non_cfg_phy *ncphy = + (struct iwlagn_non_cfg_phy *)rx_resp->non_cfg_phy_buf; + u32 val, rssi_a, rssi_b, rssi_c, max_rssi; + u8 agc; + + val = le32_to_cpu(ncphy->non_cfg_phy[IWLAGN_RX_RES_AGC_IDX]); + agc = (val & IWLAGN_OFDM_AGC_MSK) >> IWLAGN_OFDM_AGC_BIT_POS; + + /* Find max rssi among 3 possible receivers. + * These values are measured by the digital signal processor (DSP). + * They should stay fairly constant even as the signal strength varies, + * if the radio's automatic gain control (AGC) is working right. + * AGC value (see below) will provide the "interesting" info. + */ + val = le32_to_cpu(ncphy->non_cfg_phy[IWLAGN_RX_RES_RSSI_AB_IDX]); + rssi_a = (val & IWLAGN_OFDM_RSSI_INBAND_A_BITMSK) >> + IWLAGN_OFDM_RSSI_A_BIT_POS; + rssi_b = (val & IWLAGN_OFDM_RSSI_INBAND_B_BITMSK) >> + IWLAGN_OFDM_RSSI_B_BIT_POS; + val = le32_to_cpu(ncphy->non_cfg_phy[IWLAGN_RX_RES_RSSI_C_IDX]); + rssi_c = (val & IWLAGN_OFDM_RSSI_INBAND_C_BITMSK) >> + IWLAGN_OFDM_RSSI_C_BIT_POS; + + max_rssi = max_t(u32, rssi_a, rssi_b); + max_rssi = max_t(u32, max_rssi, rssi_c); + + IWL_DEBUG_STATS(priv, "Rssi In A %d B %d C %d Max %d AGC dB %d\n", + rssi_a, rssi_b, rssi_c, max_rssi, agc); + + /* dBm = max_rssi dB - agc dB - constant. + * Higher AGC (higher radio gain) means lower signal. */ + return max_rssi - agc - IWLAGN_RSSI_OFFSET; +} + /* Called for REPLY_RX (legacy ABG frames), or * REPLY_RX_MPDU_CMD (HT high-throughput N frames). */ static void iwl_rx_reply_rx(struct iwl_priv *priv, @@ -983,7 +1024,7 @@ static void iwl_rx_reply_rx(struct iwl_priv *priv, priv->ucode_beacon_time = le32_to_cpu(phy_res->beacon_time_stamp); /* Find max signal strength (dBm) among 3 antenna/receiver chains */ - rx_status.signal = priv->cfg->ops->utils->calc_rssi(priv, phy_res); + rx_status.signal = iwlagn_calc_rssi(priv, phy_res); iwl_dbg_log_rx_data_frame(priv, len, header); IWL_DEBUG_STATS_LIMIT(priv, "Rssi %d, TSF %llu\n", |