ath5k: Debug DMA timeouts

 * Increase timeouts on ath5k_hw_stop_tx_dma and also wait for
 tx queue to stop before checking for pending frames

 * Add a new debug level to debug dma start/stop

 Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>

Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 32 insertions, 5 deletions

diff --git a/drivers/net/wireless/ath/ath5k/debug.c b/drivers/net/wireless/ath/ath5k/debug.c
index 7d785cb60ce0..5341dd2860d3 100644
--- a/drivers/net/wireless/ath/ath5k/debug.c
+++ b/drivers/net/wireless/ath/ath5k/debug.c
@@ -312,6 +312,7 @@ static const struct {
         { ATH5K_DEBUG_DUMP_RX,  "dumprx",       "print received skb content" },
         { ATH5K_DEBUG_DUMP_TX,  "dumptx",       "print transmit skb content" },
         { ATH5K_DEBUG_DUMPBANDS, "dumpbands",   "dump bands" },
+        { ATH5K_DEBUG_DMA,      "dma",          "dma start/stop" },
         { ATH5K_DEBUG_ANI,      "ani",          "adaptive noise immunity" },
         { ATH5K_DEBUG_DESC,     "desc",         "descriptor chains" },
         { ATH5K_DEBUG_ANY,      "all",          "show all debug levels" },
diff --git a/drivers/net/wireless/ath/ath5k/debug.h b/drivers/net/wireless/ath/ath5k/debug.h
index 236edbd2507d..3e34428d5126 100644
--- a/drivers/net/wireless/ath/ath5k/debug.h
+++ b/drivers/net/wireless/ath/ath5k/debug.h
@@ -95,6 +95,7 @@ struct ath5k_dbg_info {
  * @ATH5K_DEBUG_DUMP_RX: print received skb content
  * @ATH5K_DEBUG_DUMP_TX: print transmit skb content
  * @ATH5K_DEBUG_DUMPBANDS: dump bands
+ * @ATH5K_DEBUG_DMA: debug dma start/stop
  * @ATH5K_DEBUG_TRACE: trace function calls
  * @ATH5K_DEBUG_DESC: descriptor setup
  * @ATH5K_DEBUG_ANY: show at any debug level
@@ -118,6 +119,7 @@ enum ath5k_debug_level {
         ATH5K_DEBUG_DUMP_RX     = 0x00000100,
         ATH5K_DEBUG_DUMP_TX     = 0x00000200,
         ATH5K_DEBUG_DUMPBANDS   = 0x00000400,
+        ATH5K_DEBUG_DMA         = 0x00000800,
         ATH5K_DEBUG_ANI         = 0x00002000,
         ATH5K_DEBUG_DESC        = 0x00004000,
         ATH5K_DEBUG_ANY         = 0xffffffff
diff --git a/drivers/net/wireless/ath/ath5k/dma.c b/drivers/net/wireless/ath/ath5k/dma.c
index ca0467e21e56..e39c95340841 100644
--- a/drivers/net/wireless/ath/ath5k/dma.c
+++ b/drivers/net/wireless/ath/ath5k/dma.c
@@ -70,7 +70,11 @@ int ath5k_hw_stop_rx_dma(struct ath5k_hw *ah)
         for (i = 1000; i > 0 &&
                         (ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) != 0;
                         i--)
-                udelay(10);
+                udelay(100);
+
+        if (i)
+                ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+                                "failed to stop RX DMA !\n");
 
         return i ? 0 : -EBUSY;
 }
@@ -217,7 +221,18 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
                  */
                 AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXD, queue);
 
-                /*Check for pending frames*/
+                /* Wait for queue to stop */
+                for (i = 1000; i > 0 &&
+                (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue) != 0);
+                i--)
+                        udelay(100);
+
+                if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
+                        ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+                                "queue %i didn't stop !\n", queue);
+
+                /* Check for pending frames */
+                i = 1000;
                 do {
                         pending = ath5k_hw_reg_read(ah,
                                 AR5K_QUEUE_STATUS(queue)) &
@@ -248,12 +263,12 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
                                         AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
 
                         /* Wait a while and disable mechanism */
-                        udelay(200);
+                        udelay(400);
                         AR5K_REG_DISABLE_BITS(ah, AR5K_QUIET_CTL1,
                                                 AR5K_QUIET_CTL1_QT_EN);
 
                         /* Re-check for pending frames */
-                        i = 40;
+                        i = 100;
                         do {
                                 pending = ath5k_hw_reg_read(ah,
                                         AR5K_QUEUE_STATUS(queue)) &
@@ -263,12 +278,21 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
 
                         AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW_5211,
                                         AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
+
+                        if (pending)
+                                ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+                                        "quiet mechanism didn't work q:%i !\n",
+                                        queue);
                 }
 
                 /* Clear register */
                 ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
-                if (pending)
+                if (pending) {
+                        ATH5K_DBG(ah->ah_sc, ATH5K_DEBUG_DMA,
+                                        "tx dma didn't stop (q:%i, frm:%i) !\n",
+                                        queue, pending);
                         return -EBUSY;
+                }
         }
 
         /* TODO: Check for success on 5210 else return error */