iwlwifi: mvm: update the rssi calculation

Make the rssi more accurate by taking in count per-chain AGC
values. Without this, the RSSI reports inaccurate values.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/iwlwifi/mvm/fw-api.h b/drivers/net/wireless/iwlwifi/mvm/fw-api.h
index 23eebda..2adb61f 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/fw-api.h
+++ b/drivers/net/wireless/iwlwifi/mvm/fw-api.h
@@ -762,18 +762,20 @@ struct iwl_phy_context_cmd {
 #define IWL_RX_INFO_PHY_CNT 8
 #define IWL_RX_INFO_AGC_IDX 1
 #define IWL_RX_INFO_RSSI_AB_IDX 2
-#define IWL_RX_INFO_RSSI_C_IDX 3
-#define IWL_OFDM_AGC_DB_MSK 0xfe00
-#define IWL_OFDM_AGC_DB_POS 9
+#define IWL_OFDM_AGC_A_MSK 0x0000007f
+#define IWL_OFDM_AGC_A_POS 0
+#define IWL_OFDM_AGC_B_MSK 0x00003f80
+#define IWL_OFDM_AGC_B_POS 7
+#define IWL_OFDM_AGC_CODE_MSK 0x3fe00000
+#define IWL_OFDM_AGC_CODE_POS 20
 #define IWL_OFDM_RSSI_INBAND_A_MSK 0x00ff
-#define IWL_OFDM_RSSI_ALLBAND_A_MSK 0xff00
 #define IWL_OFDM_RSSI_A_POS 0
+#define IWL_OFDM_RSSI_ALLBAND_A_MSK 0xff00
+#define IWL_OFDM_RSSI_ALLBAND_A_POS 8
 #define IWL_OFDM_RSSI_INBAND_B_MSK 0xff0000
-#define IWL_OFDM_RSSI_ALLBAND_B_MSK 0xff000000
 #define IWL_OFDM_RSSI_B_POS 16
-#define IWL_OFDM_RSSI_INBAND_C_MSK 0x00ff
-#define IWL_OFDM_RSSI_ALLBAND_C_MSK 0xff00
-#define IWL_OFDM_RSSI_C_POS 0
+#define IWL_OFDM_RSSI_ALLBAND_B_MSK 0xff000000
+#define IWL_OFDM_RSSI_ALLBAND_B_POS 24
 
 /**
  * struct iwl_rx_phy_info - phy info

diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index 537711b..bdae700 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -80,7 +80,8 @@
 
 #define IWL_INVALID_MAC80211_QUEUE     0xff
 #define IWL_MVM_MAX_ADDRESSES          2
-#define IWL_RSSI_OFFSET 44
+/* RSSI offset for WkP */
+#define IWL_RSSI_OFFSET 50
 
 enum iwl_mvm_tx_fifo {
        IWL_MVM_TX_FIFO_BK = 0,

diff --git a/drivers/net/wireless/iwlwifi/mvm/rx.c b/drivers/net/wireless/iwlwifi/mvm/rx.c
index 3f40ab0..b0b190d 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/rx.c
@@ -131,33 +131,42 @@ static void iwl_mvm_pass_packet_to_mac80211(struct iwl_mvm *mvm,
 static int iwl_mvm_calc_rssi(struct iwl_mvm *mvm,
                             struct iwl_rx_phy_info *phy_info)
 {
-       u32 rssi_a, rssi_b, rssi_c, max_rssi, agc_db;
+       int rssi_a, rssi_b, rssi_a_dbm, rssi_b_dbm, max_rssi_dbm;
+       int rssi_all_band_a, rssi_all_band_b;
+       u32 agc_a, agc_b, max_agc;
        u32 val;
 
-       /* Find max rssi among 3 possible receivers.
+       /* Find max rssi among 2 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(phy_info->non_cfg_phy[IWL_RX_INFO_AGC_IDX]);
+       agc_a = (val & IWL_OFDM_AGC_A_MSK) >> IWL_OFDM_AGC_A_POS;
+       agc_b = (val & IWL_OFDM_AGC_B_MSK) >> IWL_OFDM_AGC_B_POS;
+       max_agc = max_t(u32, agc_a, agc_b);
+
        val = le32_to_cpu(phy_info->non_cfg_phy[IWL_RX_INFO_RSSI_AB_IDX]);
        rssi_a = (val & IWL_OFDM_RSSI_INBAND_A_MSK) >> IWL_OFDM_RSSI_A_POS;
        rssi_b = (val & IWL_OFDM_RSSI_INBAND_B_MSK) >> IWL_OFDM_RSSI_B_POS;
-       val = le32_to_cpu(phy_info->non_cfg_phy[IWL_RX_INFO_RSSI_C_IDX]);
-       rssi_c = (val & IWL_OFDM_RSSI_INBAND_C_MSK) >> IWL_OFDM_RSSI_C_POS;
-
-       val = le32_to_cpu(phy_info->non_cfg_phy[IWL_RX_INFO_AGC_IDX]);
-       agc_db = (val & IWL_OFDM_AGC_DB_MSK) >> IWL_OFDM_AGC_DB_POS;
+       rssi_all_band_a = (val & IWL_OFDM_RSSI_ALLBAND_A_MSK) >>
+                               IWL_OFDM_RSSI_ALLBAND_A_POS;
+       rssi_all_band_b = (val & IWL_OFDM_RSSI_ALLBAND_B_MSK) >>
+                               IWL_OFDM_RSSI_ALLBAND_B_POS;
 
-       max_rssi = max_t(u32, rssi_a, rssi_b);
-       max_rssi = max_t(u32, max_rssi, rssi_c);
+       /*
+        * dBm = rssi dB - agc dB - constant.
+        * Higher AGC (higher radio gain) means lower signal.
+        */
+       rssi_a_dbm = rssi_a - IWL_RSSI_OFFSET - agc_a;
+       rssi_b_dbm = rssi_b - IWL_RSSI_OFFSET - agc_b;
+       max_rssi_dbm = max_t(int, rssi_a_dbm, rssi_b_dbm);
 
-       IWL_DEBUG_STATS(mvm, "Rssi In A %d B %d C %d Max %d AGC dB %d\n",
-                       rssi_a, rssi_b, rssi_c, max_rssi, agc_db);
+       IWL_DEBUG_STATS(mvm, "Rssi In A %d B %d Max %d AGCA %d AGCB %d\n",
+                       rssi_a_dbm, rssi_b_dbm, max_rssi_dbm, agc_a, agc_b);
 
-       /* dBm = max_rssi dB - agc dB - constant.
-        * Higher AGC (higher radio gain) means lower signal. */
-       return max_rssi - agc_db - IWL_RSSI_OFFSET;
+       return max_rssi_dbm;
 }
 
 /*