1 files changed, 72 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_hw.c b/drivers/net/wireless/ath/ath9k/ar9003_hw.c
index f1d3c4aa2396..75a6d85d6ee9 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_hw.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_hw.c
@@ -892,6 +892,77 @@ static void ar9003_hw_init_hang_checks(struct ath_hw *ah)
                 ah->bb_watchdog_timeout_ms = 25;
 }
 
+static bool ath9k_hw_check_dcs(u32 dma_dbg, u32 num_dcu_states,
+                               int *hang_state, int *hang_pos)
+{
+        static u32 dcu_chain_state[] = {5, 6, 9}; /* DCU chain stuck states */
+        u32 chain_state, dcs_pos, i;
+
+        for (dcs_pos = 0; dcs_pos < num_dcu_states; dcs_pos++) {
+                chain_state = (dma_dbg >> (5 * dcs_pos)) & 0x1f;
+                for (i = 0; i < 3; i++) {
+                        if (chain_state == dcu_chain_state[i]) {
+                                *hang_state = chain_state;
+                                *hang_pos = dcs_pos;
+                                return true;
+                        }
+                }
+        }
+        return false;
+}
+
+#define DCU_COMPLETE_STATE        1
+#define DCU_COMPLETE_STATE_MASK 0x3
+#define NUM_STATUS_READS         50
+
+static bool ar9003_hw_detect_mac_hang(struct ath_hw *ah)
+{
+        u32 chain_state, comp_state, dcs_reg = AR_DMADBG_4;
+        u32 i, hang_pos, hang_state, num_state = 6;
+
+        comp_state = REG_READ(ah, AR_DMADBG_6);
+
+        if ((comp_state & DCU_COMPLETE_STATE_MASK) != DCU_COMPLETE_STATE) {
+                ath_dbg(ath9k_hw_common(ah), RESET,
+                        "MAC Hang signature not found at DCU complete\n");
+                return false;
+        }
+
+        chain_state = REG_READ(ah, dcs_reg);
+        if (ath9k_hw_check_dcs(chain_state, num_state, &hang_state, &hang_pos))
+                goto hang_check_iter;
+
+        dcs_reg = AR_DMADBG_5;
+        num_state = 4;
+        chain_state = REG_READ(ah, dcs_reg);
+        if (ath9k_hw_check_dcs(chain_state, num_state, &hang_state, &hang_pos))
+                goto hang_check_iter;
+
+        ath_dbg(ath9k_hw_common(ah), RESET,
+                "MAC Hang signature 1 not found\n");
+        return false;
+
+hang_check_iter:
+        ath_dbg(ath9k_hw_common(ah), RESET,
+                "DCU registers: chain %08x complete %08x Hang: state %d pos %d\n",
+                chain_state, comp_state, hang_state, hang_pos);
+
+        for (i = 0; i < NUM_STATUS_READS; i++) {
+                chain_state = REG_READ(ah, dcs_reg);
+                chain_state = (chain_state >> (5 * hang_pos)) & 0x1f;
+                comp_state = REG_READ(ah, AR_DMADBG_6);
+
+                if (((comp_state & DCU_COMPLETE_STATE_MASK) !=
+                                        DCU_COMPLETE_STATE) ||
+                    (chain_state != hang_state))
+                        return false;
+        }
+
+        ath_dbg(ath9k_hw_common(ah), RESET, "MAC Hang signature 1 found\n");
+
+        return true;
+}
+
 /* Sets up the AR9003 hardware familiy callbacks */
 void ar9003_hw_attach_ops(struct ath_hw *ah)
 {
@@ -901,6 +972,7 @@ void ar9003_hw_attach_ops(struct ath_hw *ah)
         ar9003_hw_init_mode_regs(ah);
         priv_ops->init_mode_gain_regs = ar9003_hw_init_mode_gain_regs;
         priv_ops->init_hang_checks = ar9003_hw_init_hang_checks;
+        priv_ops->detect_mac_hang = ar9003_hw_detect_mac_hang;
 
         ops->config_pci_powersave = ar9003_hw_configpcipowersave;