wil6210: limit fw error recovery attempts

In case there is something fundamentally wrong with the firmware
(example: RF cable disconnected), FW will always crash immediately
after reset. This leads to infinite fw error recovery loop.

Count consecutive unsuccessful error recovery attempts in a short period
of time, and stop doing recovery after some reasonable count.
It is still possible to manually reset fw doing
interface down/up sequence.

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 25 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/wil6210/main.c b/drivers/net/wireless/ath/wil6210/main.c
index 670cc6de3b4c..f24cb92cc185 100644
--- a/drivers/net/wireless/ath/wil6210/main.c
+++ b/drivers/net/wireless/ath/wil6210/main.c
@@ -161,12 +161,30 @@ static void wil_fw_error_worker(struct work_struct *work)
         if (no_fw_recovery)
                 return;
 
+        /* increment @recovery_count if less then WIL6210_FW_RECOVERY_TO
+         * passed since last recovery attempt
+         */
+        if (time_is_after_jiffies(wil->last_fw_recovery +
+                                  WIL6210_FW_RECOVERY_TO))
+                wil->recovery_count++;
+        else
+                wil->recovery_count = 1; /* fw was alive for a long time */
+
+        if (wil->recovery_count > WIL6210_FW_RECOVERY_RETRIES) {
+                wil_err(wil, "too many recovery attempts (%d), giving up\n",
+                        wil->recovery_count);
+                return;
+        }
+
+        wil->last_fw_recovery = jiffies;
+
         mutex_lock(&wil->mutex);
         switch (wdev->iftype) {
         case NL80211_IFTYPE_STATION:
         case NL80211_IFTYPE_P2P_CLIENT:
         case NL80211_IFTYPE_MONITOR:
-                wil_info(wil, "fw error recovery started...\n");
+                wil_info(wil, "fw error recovery started (try %d)...\n",
+                         wil->recovery_count);
                 wil_reset(wil);
 
                 /* need to re-allocate Rx ring after reset */
@@ -249,6 +267,8 @@ int wil_priv_init(struct wil6210_priv *wil)
                 return -EAGAIN;
         }
 
+        wil->last_fw_recovery = jiffies;
+
         return 0;
 }
 
diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h
index 3427ac4a4fa1..f8c598ebd9ee 100644
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -40,6 +40,8 @@ static inline u32 WIL_GET_BITS(u32 x, int b0, int b1)
 #define WIL6210_MAX_CID         (8) /* HW limit */
 #define WIL6210_NAPI_BUDGET     (16) /* arbitrary */
 #define WIL6210_ITR_TRSH        (10000) /* arbitrary - about 15 IRQs/msec */
+#define WIL6210_FW_RECOVERY_RETRIES     (5) /* try to recover this many times */
+#define WIL6210_FW_RECOVERY_TO  msecs_to_jiffies(5000)
 
 /* Hardware definitions begin */
 
@@ -361,6 +363,8 @@ struct wil6210_priv {
         u32 fw_version;
         u32 hw_version;
         u8 n_mids; /* number of additional MIDs as reported by FW */
+        int recovery_count; /* num of FW recovery attempts in a short time */
+        unsigned long last_fw_recovery; /* jiffies of last fw recovery */
         /* profile */
         u32 monitor_flags;
         u32 secure_pcp; /* create secure PCP? */