10 files changed, 132 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-1000.c b/drivers/net/wireless/iwlwifi/iwl-1000.c
index d5c6edbbc95a..85162e2c35d9 100644
--- a/drivers/net/wireless/iwlwifi/iwl-1000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-1000.c
@@ -175,6 +175,7 @@ struct iwl_cfg iwl1000_bgn_cfg = {
         .use_rts_for_ht = true, /* use rts/cts protection */
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl1000_bg_cfg = {
@@ -201,6 +202,7 @@ struct iwl_cfg iwl1000_bg_cfg = {
         .led_compensation = 51,
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 MODULE_FIRMWARE(IWL1000_MODULE_FIRMWARE(IWL1000_UCODE_API_MAX));
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.c b/drivers/net/wireless/iwlwifi/iwl-3945.c
index 6472910b72d4..764479f74c8b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -2830,6 +2830,7 @@ static struct iwl_cfg iwl3945_bg_cfg = {
         .ht_greenfield_support = false,
         .led_compensation = 64,
         .broken_powersave = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 static struct iwl_cfg iwl3945_abg_cfg = {
@@ -2847,6 +2848,7 @@ static struct iwl_cfg iwl3945_abg_cfg = {
         .ht_greenfield_support = false,
         .led_compensation = 64,
         .broken_powersave = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 struct pci_device_id iwl3945_hw_card_ids[] = {
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index 8159a0fcf5a8..c36fef99b4b0 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -2239,6 +2239,7 @@ struct iwl_cfg iwl4965_agn_cfg = {
         .broken_powersave = true,
         .led_compensation = 61,
         .chain_noise_num_beacons = IWL4965_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 /* Module firmware */
diff --git a/drivers/net/wireless/iwlwifi/iwl-5000.c b/drivers/net/wireless/iwlwifi/iwl-5000.c
index aab6cf23c2bd..cbbc0e4f2c76 100644
--- a/drivers/net/wireless/iwlwifi/iwl-5000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-5000.c
@@ -1603,6 +1603,7 @@ struct iwl_cfg iwl5300_agn_cfg = {
         .led_compensation = 51,
         .use_rts_for_ht = true, /* use rts/cts protection */
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl5100_bgn_cfg = {
@@ -1627,6 +1628,7 @@ struct iwl_cfg iwl5100_bgn_cfg = {
         .led_compensation = 51,
         .use_rts_for_ht = true, /* use rts/cts protection */
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl5100_abg_cfg = {
@@ -1649,6 +1651,7 @@ struct iwl_cfg iwl5100_abg_cfg = {
         .use_bsm = false,
         .led_compensation = 51,
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl5100_agn_cfg = {
@@ -1673,6 +1676,7 @@ struct iwl_cfg iwl5100_agn_cfg = {
         .led_compensation = 51,
         .use_rts_for_ht = true, /* use rts/cts protection */
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl5350_agn_cfg = {
@@ -1697,6 +1701,7 @@ struct iwl_cfg iwl5350_agn_cfg = {
         .led_compensation = 51,
         .use_rts_for_ht = true, /* use rts/cts protection */
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl5150_agn_cfg = {
@@ -1721,6 +1726,7 @@ struct iwl_cfg iwl5150_agn_cfg = {
         .led_compensation = 51,
         .use_rts_for_ht = true, /* use rts/cts protection */
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl5150_abg_cfg = {
@@ -1743,6 +1749,7 @@ struct iwl_cfg iwl5150_abg_cfg = {
         .use_bsm = false,
         .led_compensation = 51,
         .chain_noise_num_beacons = IWL_CAL_NUM_BEACONS,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF,
 };
 
 MODULE_FIRMWARE(IWL5000_MODULE_FIRMWARE(IWL5000_UCODE_API_MAX));
diff --git a/drivers/net/wireless/iwlwifi/iwl-6000.c b/drivers/net/wireless/iwlwifi/iwl-6000.c
index 4dab7f12e725..b191c634ad92 100644
--- a/drivers/net/wireless/iwlwifi/iwl-6000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-6000.c
@@ -308,6 +308,7 @@ struct iwl_cfg iwl6000i_2agn_cfg = {
         .supports_idle = true,
         .adv_thermal_throttle = true,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl6000i_2abg_cfg = {
@@ -337,6 +338,7 @@ struct iwl_cfg iwl6000i_2abg_cfg = {
         .supports_idle = true,
         .adv_thermal_throttle = true,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl6000i_2bg_cfg = {
@@ -366,6 +368,7 @@ struct iwl_cfg iwl6000i_2bg_cfg = {
         .supports_idle = true,
         .adv_thermal_throttle = true,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl6050_2agn_cfg = {
@@ -396,6 +399,7 @@ struct iwl_cfg iwl6050_2agn_cfg = {
         .supports_idle = true,
         .adv_thermal_throttle = true,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl6050_2abg_cfg = {
@@ -425,6 +429,7 @@ struct iwl_cfg iwl6050_2abg_cfg = {
         .supports_idle = true,
         .adv_thermal_throttle = true,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 struct iwl_cfg iwl6000_3agn_cfg = {
@@ -455,6 +460,7 @@ struct iwl_cfg iwl6000_3agn_cfg = {
         .supports_idle = true,
         .adv_thermal_throttle = true,
         .support_ct_kill_exit = true,
+        .plcp_delta_threshold = IWL_MAX_PLCP_ERR_THRESHOLD_DEF,
 };
 
 MODULE_FIRMWARE(IWL6000_MODULE_FIRMWARE(IWL6000_UCODE_API_MAX));
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index 6de83d1e1eb8..661918347d48 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -232,6 +232,8 @@ struct iwl_mod_params {
  * @adv_thermal_throttle: support advance thermal throttle
  * @support_ct_kill_exit: support ct kill exit condition
  * @support_wimax_coexist: support wimax/wifi co-exist
+ * @plcp_delta_threshold: plcp error rate threshold used to trigger
+ *      radio tuning when there is a high receiving plcp error rate
  *
  * We enable the driver to be backward compatible wrt API version. The
  * driver specifies which APIs it supports (with @ucode_api_max being the
@@ -288,6 +290,7 @@ struct iwl_cfg {
         bool adv_thermal_throttle;
         bool support_ct_kill_exit;
         const bool support_wimax_coexist;
+        u8 plcp_delta_threshold;
 };
 
 /***************************
diff --git a/drivers/net/wireless/iwlwifi/iwl-debug.h b/drivers/net/wireless/iwlwifi/iwl-debug.h
index d81b4f39bb1d..aff1dc0756fc 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debug.h
+++ b/drivers/net/wireless/iwlwifi/iwl-debug.h
@@ -114,6 +114,7 @@ struct iwl_debugfs {
                 struct dentry *file_fh_reg;
                 struct dentry *file_missed_beacon;
                 struct dentry *file_internal_scan;
+                struct dentry *file_plcp_delta;
         } dbgfs_debug_files;
         u32 sram_offset;
         u32 sram_len;
diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index 4944fdb31ba8..3f9c03998491 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -2195,6 +2195,47 @@ static ssize_t iwl_dbgfs_internal_scan_write(struct file *file,
         return count;
 }
 
+static ssize_t iwl_dbgfs_plcp_delta_read(struct file *file,
+                                        char __user *user_buf,
+                                        size_t count, loff_t *ppos) {
+
+        struct iwl_priv *priv = (struct iwl_priv *)file->private_data;
+        int pos = 0;
+        char buf[12];
+        const size_t bufsz = sizeof(buf);
+        ssize_t ret;
+
+        pos += scnprintf(buf + pos, bufsz - pos, "%u\n",
+                        priv->cfg->plcp_delta_threshold);
+
+        ret = simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+        return ret;
+}
+
+static ssize_t iwl_dbgfs_plcp_delta_write(struct file *file,
+                                        const char __user *user_buf,
+                                        size_t count, loff_t *ppos) {
+
+        struct iwl_priv *priv = file->private_data;
+        char buf[8];
+        int buf_size;
+        int plcp;
+
+        memset(buf, 0, sizeof(buf));
+        buf_size = min(count, sizeof(buf) -  1);
+        if (copy_from_user(buf, user_buf, buf_size))
+                return -EFAULT;
+        if (sscanf(buf, "%d", &plcp) != 1)
+                return -EINVAL;
+        if ((plcp <= IWL_MAX_PLCP_ERR_THRESHOLD_MIN) ||
+                (plcp > IWL_MAX_PLCP_ERR_THRESHOLD_MAX))
+                priv->cfg->plcp_delta_threshold =
+                        IWL_MAX_PLCP_ERR_THRESHOLD_DEF;
+        else
+                priv->cfg->plcp_delta_threshold = plcp;
+        return count;
+}
+
 DEBUGFS_READ_FILE_OPS(rx_statistics);
 DEBUGFS_READ_FILE_OPS(tx_statistics);
 DEBUGFS_READ_WRITE_FILE_OPS(traffic_log);
@@ -2214,6 +2255,7 @@ DEBUGFS_READ_WRITE_FILE_OPS(ucode_tracing);
 DEBUGFS_READ_FILE_OPS(fh_reg);
 DEBUGFS_READ_WRITE_FILE_OPS(missed_beacon);
 DEBUGFS_WRITE_FILE_OPS(internal_scan);
+DEBUGFS_READ_WRITE_FILE_OPS(plcp_delta);
 
 /*
  * Create the debugfs files and directories
@@ -2268,6 +2310,7 @@ int iwl_dbgfs_register(struct iwl_priv *priv, const char *name)
         DEBUGFS_ADD_FILE(fh_reg, debug, S_IRUSR);
         DEBUGFS_ADD_FILE(missed_beacon, debug, S_IWUSR);
         DEBUGFS_ADD_FILE(internal_scan, debug, S_IWUSR);
+        DEBUGFS_ADD_FILE(plcp_delta, debug, S_IWUSR | S_IRUSR);
         if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) != CSR_HW_REV_TYPE_3945) {
                 DEBUGFS_ADD_FILE(ucode_rx_stats, debug, S_IRUSR);
                 DEBUGFS_ADD_FILE(ucode_tx_stats, debug, S_IRUSR);
@@ -2330,6 +2373,7 @@ void iwl_dbgfs_unregister(struct iwl_priv *priv)
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_fh_reg);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_missed_beacon);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_internal_scan);
+        DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_plcp_delta);
         if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) != CSR_HW_REV_TYPE_3945) {
                 DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.
                         file_ucode_rx_stats);
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index 86d38ae2ec7e..a1f3ecb69ed0 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -1026,6 +1026,15 @@ struct iwl_event_log {
 #define IWL_HOST_INT_CALIB_TIMEOUT_DEF  (0x10)
 #define IWL_HOST_INT_CALIB_TIMEOUT_MIN  (0x0)
 
+/*
+ * This is the threshold value of plcp error rate per 100mSecs.  It is
+ * used to set and check for the validity of plcp_delta.
+ */
+#define IWL_MAX_PLCP_ERR_THRESHOLD_MIN  (0)
+#define IWL_MAX_PLCP_ERR_THRESHOLD_DEF  (50)
+#define IWL_MAX_PLCP_ERR_LONG_THRESHOLD_DEF     (100)
+#define IWL_MAX_PLCP_ERR_THRESHOLD_MAX  (255)
+
 struct iwl_priv {
 
         /* ieee device used by generic ieee processing code */
@@ -1055,6 +1064,9 @@ struct iwl_priv {
         u32 ucode_beacon_time;
         int missed_beacon_threshold;
 
+        /* storing the jiffies when the plcp error rate is received */
+        unsigned long plcp_jiffies;
+
         /* we allocate array of iwl4965_channel_info for NIC's valid channels.
          *    Access via channel # using indirect index array */
         struct iwl_channel_info *channel_info;  /* channel info array */
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index dc06c7bb0f5c..ea309f42a78a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -602,11 +602,15 @@ static void iwl_accumulative_statistics(struct iwl_priv *priv,
 
 #define REG_RECALIB_PERIOD (60)
 
+#define PLCP_MSG "plcp_err exceeded %u, %u, %u, %u, %u, %d, %u mSecs\n"
 void iwl_rx_statistics(struct iwl_priv *priv,
                               struct iwl_rx_mem_buffer *rxb)
 {
         int change;
         struct iwl_rx_packet *pkt = rxb_addr(rxb);
+        int combined_plcp_delta;
+        unsigned int plcp_msec;
+        unsigned long plcp_received_jiffies;
 
         IWL_DEBUG_RX(priv, "Statistics notification received (%d vs %d).\n",
                      (int)sizeof(priv->statistics),
@@ -621,6 +625,56 @@ void iwl_rx_statistics(struct iwl_priv *priv,
 #ifdef CONFIG_IWLWIFI_DEBUG
         iwl_accumulative_statistics(priv, (__le32 *)&pkt->u.stats);
 #endif
+        /*
+         * check for plcp_err and trigger radio reset if it exceeds
+         * the plcp error threshold plcp_delta.
+         */
+        plcp_received_jiffies = jiffies;
+        plcp_msec = jiffies_to_msecs((long) plcp_received_jiffies -
+                                        (long) priv->plcp_jiffies);
+        priv->plcp_jiffies = plcp_received_jiffies;
+        /*
+         * check to make sure plcp_msec is not 0 to prevent division
+         * by zero.
+         */
+        if (plcp_msec) {
+                combined_plcp_delta =
+                        (le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err) -
+                        le32_to_cpu(priv->statistics.rx.ofdm.plcp_err)) +
+                        (le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err) -
+                        le32_to_cpu(priv->statistics.rx.ofdm_ht.plcp_err));
+
+                if ((combined_plcp_delta > 0) &&
+                        ((combined_plcp_delta * 100) / plcp_msec) >
+                        priv->cfg->plcp_delta_threshold) {
+                        /*
+                         * if plcp_err exceed the threshold, the following
+                         * data is printed in csv format:
+                         *    Text: plcp_err exceeded %d,
+                         *    Received ofdm.plcp_err,
+                         *    Current ofdm.plcp_err,
+                         *    Received ofdm_ht.plcp_err,
+                         *    Current ofdm_ht.plcp_err,
+                         *    combined_plcp_delta,
+                         *    plcp_msec
+                         */
+                        IWL_DEBUG_RADIO(priv, PLCP_MSG,
+                                priv->cfg->plcp_delta_threshold,
+                                le32_to_cpu(pkt->u.stats.rx.ofdm.plcp_err),
+                                le32_to_cpu(priv->statistics.rx.ofdm.plcp_err),
+                                le32_to_cpu(pkt->u.stats.rx.ofdm_ht.plcp_err),
+                                le32_to_cpu(
+                                        priv->statistics.rx.ofdm_ht.plcp_err),
+                                combined_plcp_delta, plcp_msec);
+
+                        /*
+                         * Reset the RF radio due to the high plcp
+                         * error rate
+                         */
+                        iwl_force_rf_reset(priv);
+                }
+        }
+
         memcpy(&priv->statistics, &pkt->u.stats, sizeof(priv->statistics));
 
         set_bit(STATUS_STATISTICS, &priv->status);