ath9k_hw: disable phy restart on baseband panic caused by RXSM

While receiving unsupported rate frame rx state machine
gets into a state 0xb and if phy_restart happens in that
state, BB would go hang. If RXSM is in 0xb state after
first bb panic, ensure to disable the phy_restart.

Signed-off-by: Rajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 28 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_phy.c b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
index eee23ecd118..892c48b1543 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_phy.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_phy.c
@@ -1381,3 +1381,25 @@ void ar9003_hw_bb_watchdog_dbg_info(struct ath_hw *ah)
                 "==== BB update: done ====\n\n");
 }
 EXPORT_SYMBOL(ar9003_hw_bb_watchdog_dbg_info);
+
+void ar9003_hw_disable_phy_restart(struct ath_hw *ah)
+{
+        u32 val;
+
+        /* While receiving unsupported rate frame rx state machine
+         * gets into a state 0xb and if phy_restart happens in that
+         * state, BB would go hang. If RXSM is in 0xb state after
+         * first bb panic, ensure to disable the phy_restart.
+         */
+        if (!((MS(ah->bb_watchdog_last_status,
+                  AR_PHY_WATCHDOG_RX_OFDM_SM) == 0xb) ||
+            ah->bb_hang_rx_ofdm))
+                return;
+
+        ah->bb_hang_rx_ofdm = true;
+        val = REG_READ(ah, AR_PHY_RESTART);
+        val &= ~AR_PHY_RESTART_ENA;
+
+        REG_WRITE(ah, AR_PHY_RESTART, val);
+}
+EXPORT_SYMBOL(ar9003_hw_disable_phy_restart);
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 72543ce8f61..1be7c8bbef8 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1555,9 +1555,12 @@ int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan,
         if (ah->btcoex_hw.enabled)
                 ath9k_hw_btcoex_enable(ah);
 
-        if (AR_SREV_9300_20_OR_LATER(ah))
+        if (AR_SREV_9300_20_OR_LATER(ah)) {
                 ar9003_hw_bb_watchdog_config(ah);
 
+                ar9003_hw_disable_phy_restart(ah);
+        }
+
         ath9k_hw_apply_gpio_override(ah);
 
         return 0;
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 57435ce6279..4b157c53d1a 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -842,6 +842,7 @@ struct ath_hw {
 
         u32 bb_watchdog_last_status;
         u32 bb_watchdog_timeout_ms; /* in ms, 0 to disable */
+        u8 bb_hang_rx_ofdm; /* true if bb hang due to rx_ofdm */
 
         unsigned int paprd_target_power;
         unsigned int paprd_training_power;
@@ -990,6 +991,7 @@ void ar9002_hw_enable_wep_aggregation(struct ath_hw *ah);
 void ar9003_hw_bb_watchdog_config(struct ath_hw *ah);
 void ar9003_hw_bb_watchdog_read(struct ath_hw *ah);
 void ar9003_hw_bb_watchdog_dbg_info(struct ath_hw *ah);
+void ar9003_hw_disable_phy_restart(struct ath_hw *ah);
 void ar9003_paprd_enable(struct ath_hw *ah, bool val);
 void ar9003_paprd_populate_single_table(struct ath_hw *ah,
                                         struct ath9k_hw_cal_data *caldata,