iwlwifi: Recover TX flow stall due to stuck queue

Monitors the internal TX queues periodically.  When a queue is stuck
for some unknown conditions causing the throughput to drop and the
transfer is stop, the driver will force firmware reload and bring the
system back to normal operational state.

The iwlwifi devices behave differently in this regard so this feature is
made part of the ops infrastructure so we can have more control on how to
monitor and recover from tx queue stall case per device.

Signed-off-by: Trieu 'Andrew' Nguyen <trieux.t.nguyen@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index 9c676ea420b9..bb4cba508acf 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -183,6 +183,10 @@ struct iwl_queue {
         int n_bd;              /* number of BDs in this queue */
         int write_ptr;       /* 1-st empty entry (index) host_w*/
         int read_ptr;         /* last used entry (index) host_r*/
+        /* use for monitoring and recovering the stuck queue */
+        int last_read_ptr;      /* storing the last read_ptr */
+        /* number of time read_ptr and last_read_ptr are the same */
+        u8 repeat_same_read_ptr;
         dma_addr_t dma_addr;   /* physical addr for BD's */
         int n_window;          /* safe queue window */
         u32 id;
@@ -1044,6 +1048,11 @@ struct iwl_event_log {
 #define IWL_DELAY_NEXT_FORCE_RF_RESET  (HZ*3)
 #define IWL_DELAY_NEXT_FORCE_FW_RELOAD (HZ*5)
 
+/* timer constants use to monitor and recover stuck tx queues in mSecs */
+#define IWL_MONITORING_PERIOD  (1000)
+#define IWL_ONE_HUNDRED_MSECS   (100)
+#define IWL_SIXTY_SECS          (60000)
+
 enum iwl_reset {
         IWL_RF_RESET = 0,
         IWL_FW_RESET,
@@ -1354,6 +1363,7 @@ struct iwl_priv {
         struct work_struct run_time_calib_work;
         struct timer_list statistics_periodic;
         struct timer_list ucode_trace;
+        struct timer_list monitor_recover;
         bool hw_ready;
 
         struct iwl_event_log event_log;