ath9k: Fix a DMA latency issue for Intel Pinetrail platforms.

Throughput was severely affected in Intel Pinetrail platforms
because of a DMA problem in C3 state. This patch fixes this
issue.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
CC: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index cf6fa54..09dcdd7 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -15,6 +15,7 @@
  */
 
 #include <linux/nl80211.h>
+#include <linux/pm_qos_params.h>
 #include "ath9k.h"
 #include "btcoex.h"
 
@@ -1239,6 +1240,8 @@
 			ath9k_btcoex_timer_resume(sc);
 	}
 
+	pm_qos_update_request(&ath9k_pm_qos_req, 55);
+
 mutex_unlock:
 	mutex_unlock(&sc->mutex);
 
@@ -1416,6 +1419,8 @@
 
 	sc->sc_flags |= SC_OP_INVALID;
 
+	pm_qos_update_request(&ath9k_pm_qos_req, PM_QOS_DEFAULT_VALUE);
+
 	mutex_unlock(&sc->mutex);
 
 	ath_print(common, ATH_DBG_CONFIG, "Driver halt\n");