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

[Mohammed Shafi <mshajakhan@atheros.com>]

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...
>    
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
>>
>>
>>      
>