iwlagn: keep track fail tx reason counter

If uCode fail to transmit frame, it will send reply tx back
to driver with failure status; keep the counters of each failure
cases for debugging.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index 4e3a692..bfa4864 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -957,6 +957,33 @@
 	u32 unhandled;
 };
 
+/* reply_tx_statistics (for _agn devices) */
+struct reply_tx_error_statistics {
+	u32 pp_delay;
+	u32 pp_few_bytes;
+	u32 pp_bt_prio;
+	u32 pp_quiet_period;
+	u32 pp_calc_ttak;
+	u32 int_crossed_retry;
+	u32 short_limit;
+	u32 long_limit;
+	u32 fifo_underrun;
+	u32 drain_flow;
+	u32 rfkill_flush;
+	u32 life_expire;
+	u32 dest_ps;
+	u32 host_abort;
+	u32 bt_retry;
+	u32 sta_invalid;
+	u32 frag_drop;
+	u32 tid_disable;
+	u32 fifo_flush;
+	u32 insuff_cf_poll;
+	u32 fail_hw_drop;
+	u32 sta_color_mismatch;
+	u32 unknown;
+};
+
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 /* management statistics */
 enum iwl_mgmt_stats {
@@ -1415,6 +1442,8 @@
 
 			struct iwl_notif_statistics statistics;
 			struct iwl_bt_notif_statistics statistics_bt;
+			/* counts reply_tx error */
+			struct reply_tx_error_statistics reply_tx_stats;
 #ifdef CONFIG_IWLWIFI_DEBUGFS
 			struct iwl_notif_statistics accum_statistics;
 			struct iwl_notif_statistics delta_statistics;