Re: [RFC] ath9k: Fix ath9k prevents CPU to enter C3 states

["John W. Linville" <linville@tuxdriver.com>]

On Fri, Mar 04, 2011 at 11:36:37AM +0530, Mohammed Shafi wrote:
> On Wednesday 16 February 2011 10:35 AM, Mohammed Shafi wrote:
> >On Tuesday 15 February 2011 09:42 PM, John W. Linville wrote:
> >>Despite the [RFC], I am applying this.  I should have reverted all
> >>of this three weeks ago...
> John can you please push this to stable kernel ?

Stable folks, this is the commit in Linus's tree;

commit 0f5cd45960173ba5b36727decbb4a241cbd35ef9
Author: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Date:   Tue Feb 15 21:29:32 2011 +0530

    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>

> >Thanks John.
> >>John
> >>
> >>On Tue, Feb 15, 2011 at 09:29:32PM +0530, Mohammed Shafi
> >>Shajakhan wrote:
> >>>From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
> >>>
> >>>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: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
> >>>---
> >>>  drivers/net/wireless/ath/ath9k/ath9k.h |    5 -----
> >>>  drivers/net/wireless/ath/ath9k/init.c  |    7 -------
> >>>  drivers/net/wireless/ath/ath9k/main.c  |    8 --------
> >>>  3 files changed, 0 insertions(+), 20 deletions(-)
> >>>
> >>>diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h
> >>>b/drivers/net/wireless/ath/ath9k/ath9k.h
> >>>index ba436cd..0052f64 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"
> >>>@@ -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))
> >>>
> >>>@@ -650,7 +647,6 @@ struct ath_softc {
> >>>
> >>>      struct ath_ant_comb ant_comb;
> >>>
> >>>-    struct pm_qos_request_list pm_qos_req;
> >>>  };
> >>>
> >>>  void ath9k_tasklet(unsigned long data);
> >>>@@ -665,7 +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 e5c1eea..8fed4e4 100644
> >>>--- a/drivers/net/wireless/ath/ath9k/init.c
> >>>+++ b/drivers/net/wireless/ath/ath9k/init.c
> >>>@@ -41,9 +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 */
> >>>@@ -760,9 +757,6 @@ 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:
> >>>@@ -819,7 +813,6 @@ void ath9k_deinit_device(struct ath_softc *sc)
> >>>      ath9k_ps_restore(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 4f568b8..1d2c7c3 100644
> >>>--- a/drivers/net/wireless/ath/ath9k/main.c
> >>>+++ b/drivers/net/wireless/ath/ath9k/main.c
> >>>@@ -1117,12 +1117,6 @@ 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);
> >>>
> >>>@@ -1267,8 +1261,6 @@ 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");
> >>>-- 
> >>>1.7.0.4
> >>>
> >>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
John W. Linville		Someday the world will need a hero, and you
linville@tuxdriver.com			might be all we have.  Be ready.