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Commit 8101a7f0 authored by Emmanuel Grumbach's avatar Emmanuel Grumbach Committed by Johannes Berg
Browse files

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: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent f9aa8dd3

drivers/net/wireless/iwlwifi/mvm/fw-api.h

+10 −8
Original line number Diff line number Diff line
@@ -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

drivers/net/wireless/iwlwifi/mvm/mvm.h

+2 −1
Original line number Diff line number Diff line
@@ -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,

drivers/net/wireless/iwlwifi/mvm/rx.c

+23 −14
Original line number Diff line number Diff line
@@ -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;

}



/*