ath9k: Fix ath9k prevents CPU to enter C3 states

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>
Acked-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index c0b60ce38dfec946a80dba2f5e9f26f152657614..94bd9bc21a5f3406386d804c435f012144fb5e8e 100644 (file)
--- 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 14b8ab386daff8823bcc3301fa52d467ce6cb01b..91d9b2ad84d8d853bd9d587c89146e59c51df5d2 100644 (file)
--- 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 d1b0db4b9cf3d8b9a3673d25d0858ed575194895..cb0b2b983b26350185a8089c53788c6192d543c7 100644 (file)
--- 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");