ath9k: Fix ath9k prevents CPU to enter C3 states

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

This reverts the following commits:

	98c316e348bedffa730e6f1e4baeb8a3c3e0f28b
	4dc3530df7c0428b41c00399a7ee8c929406d181
	10598c124ecabbbfd7522f74de19b8f7d52a1bee

Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 23838e3..1a7fa6e 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"
@@ -57,8 +56,6 @@ struct ath_node;
 
 #define A_MAX(a, b) ((a) > (b) ? (a) : (b))
 
-#define ATH9K_PM_QOS_DEFAULT_VALUE     55
-
 #define TSF_TO_TU(_h,_l) \
        ((((u32)(_h)) << 22) | (((u32)(_l)) >> 10))
 
@@ -633,8 +630,6 @@ struct ath_softc {
        struct ath_descdma txsdma;
 
        struct ath_ant_comb ant_comb;
-
-       struct pm_qos_request_list pm_qos_req;
 };
 
 struct ath_wiphy {
@@ -666,7 +661,6 @@ static inline void ath_read_cachesize(struct ath_common *common, int *csz)
 extern struct ieee80211_ops ath9k_ops;
 extern int ath9k_modparam_nohwcrypt;
 extern int led_blink;
-extern int ath9k_pm_qos_value;
 extern bool is_ath9k_unloaded;
 
 irqreturn_t ath_isr(int irq, void *dev);

diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 087a6a9..a033d01 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -41,10 +41,6 @@ static int ath9k_btcoex_enable;
 module_param_named(btcoex_enable, ath9k_btcoex_enable, int, 0444);
 MODULE_PARM_DESC(btcoex_enable, "Enable wifi-BT coexistence");
 
-int ath9k_pm_qos_value = ATH9K_PM_QOS_DEFAULT_VALUE;
-module_param_named(pmqos, ath9k_pm_qos_value, int, S_IRUSR | S_IRGRP | S_IROTH);
-MODULE_PARM_DESC(pmqos, "User specified PM-QOS value");
-
 bool is_ath9k_unloaded;
 /* We use the hw_value as an index into our private channel structure */
 
@@ -762,9 +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:
@@ -831,7 +824,6 @@ 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 da5c645..a09d15f 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1173,12 +1173,6 @@ static int ath9k_start(struct ieee80211_hw *hw)
                        ath9k_btcoex_timer_resume(sc);
        }
 
-       /* User has the option to provide pm-qos value as a module
-        * parameter rather than using the default value of
-        * 'ATH9K_PM_QOS_DEFAULT_VALUE'.
-        */
-       pm_qos_update_request(&sc->pm_qos_req, ath9k_pm_qos_value);
-
        if (ah->caps.pcie_lcr_extsync_en && common->bus_ops->extn_synch_en)
                common->bus_ops->extn_synch_en(common);
 
@@ -1345,8 +1339,6 @@ 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_dbg(common, ATH_DBG_CONFIG, "Driver halt\n");