[PATCH] ath9k: Fix ath9k prevents CPU to enter C3 states

["Thomas Bächler" <thomas@archlinux.org>]

This is a backport of upstream commit 0f5cd45960173ba5b36727decbb4a241cbd35ef9.

The DMA latency issue is observed only in Intel pinetrail platforms
but in the driver we had a default PM-QOS value of 55. This caused
unnecessary power consumption and battery drain in other platforms.

Remove the pm-qos thing in the driver code and address the throughput
issue in Intel pinetrail platfroms in user space using any one of
the scripts in below links:

http://www.kernel.org/pub/linux/kernel/people/mcgrof/scripts/cpudmalatency.c
http://johannes.sipsolutions.net/files/netlatency.c.txt

More details can be found in the following bugzilla link:

https://bugzilla.kernel.org/show_bug.cgi?id=27532

Signed-off-by: Thomas Bächler <thomas@archlinux.org>
---

I hope this is right, it seems to work for me.
Luis or John, can you sign off on this just
to be sure?

 drivers/net/wireless/ath/ath9k/ath9k.h |    3 ---
 drivers/net/wireless/ath/ath9k/init.c  |    4 ----
 drivers/net/wireless/ath/ath9k/main.c  |    4 ----
 3 files changed, 0 insertions(+), 11 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index c0b60ce..94bd9bc 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -21,7 +21,6 @@
 #include <linux/device.h>
 #include <linux/leds.h>
 #include <linux/completion.h>
-#include <linux/pm_qos_params.h>
 
 #include "debug.h"
 #include "common.h"
@@ -647,8 +646,6 @@ struct ath_softc {
 	struct ath_descdma txsdma;
 
 	struct ath_ant_comb ant_comb;
-
-	struct pm_qos_request_list pm_qos_req;
 };
 
 struct ath_wiphy {
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 14b8ab3..91d9b2a 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -758,9 +758,6 @@ int ath9k_init_device(u16 devid, struct ath_softc *sc, u16 subsysid,
 	ath_init_leds(sc);
 	ath_start_rfkill_poll(sc);
 
-	pm_qos_add_request(&sc->pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
-			   PM_QOS_DEFAULT_VALUE);
-
 	return 0;
 
 error_world:
@@ -829,7 +826,6 @@ void ath9k_deinit_device(struct ath_softc *sc)
 	}
 
 	ieee80211_unregister_hw(hw);
-	pm_qos_remove_request(&sc->pm_qos_req);
 	ath_rx_cleanup(sc);
 	ath_tx_cleanup(sc);
 	ath9k_deinit_softc(sc);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index d1b0db4..cb0b2b9 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1245,8 +1245,6 @@ static int ath9k_start(struct ieee80211_hw *hw)
 			ath9k_btcoex_timer_resume(sc);
 	}
 
-	pm_qos_update_request(&sc->pm_qos_req, 55);
-
 mutex_unlock:
 	mutex_unlock(&sc->mutex);
 
@@ -1425,8 +1423,6 @@ static void ath9k_stop(struct ieee80211_hw *hw)
 
 	sc->sc_flags |= SC_OP_INVALID;
 
-	pm_qos_update_request(&sc->pm_qos_req, PM_QOS_DEFAULT_VALUE);
-
 	mutex_unlock(&sc->mutex);
 
 	ath_print(common, ATH_DBG_CONFIG, "Driver halt\n");
-- 
1.7.4.1