ath5k: Use DCU early termination correctly

 * DCU early termination should be used to quickly flush QCU
 according to docs so don't enable it for all queues, enable
 it only when stopping each queue and disable it when we are
 done.
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/dma.c

@@ -216,6 +216,14 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
 		ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
 		ath5k_hw_reg_read(ah, AR5K_CR);
 	} else {
+
+		/*
+		 * Enable DCU early termination to quickly
+		 * flush any pending frames from QCU
+		 */
+		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
+					AR5K_QCU_MISC_DCU_EARLY);
+
 		/*
 		 * Schedule TX disable and wait until queue is empty
 		 */
@@ -285,6 +293,12 @@ int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
 					queue);
 		}
 
+		/*
+		 * Disable DCU early termination
+		 */
+		AR5K_REG_DISABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
+					AR5K_QCU_MISC_DCU_EARLY);
+
 		/* Clear register */
 		ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
 		if (pending) {

drivers/net/wireless/ath/ath5k/qcu.c

@@ -340,9 +340,6 @@ int ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
 		/*
 		 * Set misc registers
 		 */
-		/* Enable DCU early termination for this queue */
-		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
-					AR5K_QCU_MISC_DCU_EARLY);
 
 		/* Enable DCU to wait for next fragment from QCU */
 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),