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/rx.c b/drivers/net/wireless/iwlwifi/mvm/rx.c
index 3f40ab0..b0b190d 100644
--- a/drivers/net/wireless/iwlwifi/mvm/rx.c
+++ b/drivers/net/wireless/iwlwifi/mvm/rx.c
@@ -131,33 +131,42 @@
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;
+ 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;
- 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;
+ /*
+ * 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);
- max_rssi = max_t(u32, rssi_a, rssi_b);
- max_rssi = max_t(u32, max_rssi, rssi_c);
+ 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);
- 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);
-
- /* 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;
}
/*