+static int iwl4965_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 iwl4965_rx_non_cfg_phy *ncphy =
+ (struct iwl4965_rx_non_cfg_phy *)rx_resp->non_cfg_phy_buf;
+ u32 agc = (le16_to_cpu(ncphy->agc_info) & IWL49_AGC_DB_MASK)
+ >> IWL49_AGC_DB_POS;
+
+ u32 valid_antennae =
+ (le16_to_cpu(rx_resp->phy_flags) & IWL49_RX_PHY_FLAGS_ANTENNAE_MASK)
+ >> IWL49_RX_PHY_FLAGS_ANTENNAE_OFFSET;
+ u8 max_rssi = 0;
+ u32 i;
+
+ /* 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. */
+ for (i = 0; i < 3; i++)
+ if (valid_antennae & (1 << i))
+ max_rssi = max(ncphy->rssi_info[i << 1], max_rssi);
+
+ IWL_DEBUG_STATS("Rssi In A %d B %d C %d Max %d AGC dB %d\n",
+ ncphy->rssi_info[0], ncphy->rssi_info[2], ncphy->rssi_info[4],
+ max_rssi, agc);
+
+ /* dBm = max_rssi dB - agc dB - constant.
+ * Higher AGC (higher radio gain) means lower signal. */
+ return max_rssi - agc - IWL_RSSI_OFFSET;
+}
+