ath9k_hw: Fix frequent BT rx recovery

While resuming from S3, BT host issues HCI reset command and it
causes BT firmware to busy with security key calculation. At this
movement, WLAN detects MCI hardware error of MCI_CONT_INFO_TIMEOUT
and then it starts the recovery sequence repeatedly. Too many
recovery sequences would exhaust the BT kernel message pool. This
patch imposes a duration between consecutive BT recovery procedure.
Thus it solves BT firmware panic issue reported in AR9565.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 11 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_mci.c b/drivers/net/wireless/ath/ath9k/ar9003_mci.c
index 87d9c348e598..b04fa4622822 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_mci.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_mci.c
@@ -1203,7 +1203,7 @@ EXPORT_SYMBOL(ar9003_mci_cleanup);
 u32 ar9003_mci_state(struct ath_hw *ah, u32 state_type)
 {
         struct ath9k_hw_mci *mci = &ah->btcoex_hw.mci;
-        u32 value = 0;
+        u32 value = 0, tsf;
         u8 query_type;
 
         switch (state_type) {
@@ -1261,6 +1261,14 @@ u32 ar9003_mci_state(struct ath_hw *ah, u32 state_type)
                 ar9003_mci_send_coex_bt_status_query(ah, true, query_type);
                 break;
         case MCI_STATE_RECOVER_RX:
+                tsf = ath9k_hw_gettsf32(ah);
+                if ((tsf - mci->last_recovery) <= MCI_RECOVERY_DUR_TSF) {
+                        ath_dbg(ath9k_hw_common(ah), MCI,
+                                "(MCI) ignore Rx recovery\n");
+                        break;
+                }
+                ath_dbg(ath9k_hw_common(ah), MCI, "(MCI) RECOVER RX\n");
+                mci->last_recovery = tsf;
                 ar9003_mci_prep_interface(ah);
                 mci->query_bt = true;
                 mci->need_flush_btinfo = true;
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_mci.h b/drivers/net/wireless/ath/ath9k/ar9003_mci.h
index 0910310ae834..3e51f54b0122 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_mci.h
+++ b/drivers/net/wireless/ath/ath9k/ar9003_mci.h
@@ -18,6 +18,7 @@
 #define AR9003_MCI_H
 
 #define MCI_FLAG_DISABLE_TIMESTAMP      0x00000001      /* Disable time stamp */
+#define MCI_RECOVERY_DUR_TSF            (100 * 1000)    /* 100 ms */
 
 /* Default remote BT device MCI COEX version */
 #define MCI_GPM_COEX_MAJOR_VERSION_DEFAULT  3
diff --git a/drivers/net/wireless/ath/ath9k/btcoex.h b/drivers/net/wireless/ath/ath9k/btcoex.h
index 94e921147e4c..2f84ab273d0c 100644
--- a/drivers/net/wireless/ath/ath9k/btcoex.h
+++ b/drivers/net/wireless/ath/ath9k/btcoex.h
@@ -88,6 +88,7 @@ struct ath9k_hw_mci {
         u8 bt_state;
         u8 stomp_ftp;
         bool concur_tx;
+        u32 last_recovery;
 };
 
 struct ath_btcoex_hw {