[PATCH] ath9k: make use of slot time macros

[PATCH] ath9k: make use of slot time macros

[Mohammed Shafi Shajakhan]

From: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>

Instead of using raw numbers to assign slot time it would be better to
make use of predefined slot time macros

Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
---
 drivers/net/wireless/ath/ath9k/hw.c   |    2 +-
 drivers/net/wireless/ath/ath9k/main.c |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index f9cf815..7834f75 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -411,7 +411,7 @@ static void ath9k_hw_init_defaults(struct ath_hw *ah)
 		AR_STA_ID1_CRPT_MIC_ENABLE |
 		AR_STA_ID1_MCAST_KSRCH;
 	ah->enable_32kHz_clock = DONT_USE_32KHZ;
-	ah->slottime = 20;
+	ah->slottime = ATH9K_SLOT_TIME_20;
 	ah->globaltxtimeout = (u32) -1;
 	ah->power_mode = ATH9K_PM_UNDEFINED;
 }
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index d95a576..96755c4 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1926,9 +1926,9 @@ static void ath9k_bss_info_changed(struct ieee80211_hw *hw,
 
 	if (changed & BSS_CHANGED_ERP_SLOT) {
 		if (bss_conf->use_short_slot)
-			slottime = 9;
+			slottime = ATH9K_SLOT_TIME_9;
 		else
-			slottime = 20;
+			slottime = ATH9K_SLOT_TIME_20;
 		if (vif->type == NL80211_IFTYPE_AP) {
 			/*
 			 * Defer update, so that connected stations can adjust
-- 
1.7.0.4

Re: [PATCH] ath9k: make use of slot time macros

[Felix Fietkau]

On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
> From: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
> 
> Instead of using raw numbers to assign slot time it would be better to
> make use of predefined slot time macros
How does this make it better?

- Felix

Re: [PATCH] ath9k: make use of slot time macros

[John W. Linville]

On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
> > From: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
> > 
> > Instead of using raw numbers to assign slot time it would be better to
> > make use of predefined slot time macros
> How does this make it better?

Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?

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

Re: [PATCH] ath9k: make use of slot time macros

[Felix Fietkau]

On 2011-02-11 5:15 PM, John W. Linville wrote:
> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>> > From: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
>> > 
>> > Instead of using raw numbers to assign slot time it would be better to
>> > make use of predefined slot time macros
>> How does this make it better?
> 
> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
Well, neither the unit of this variable, nor the values that can be used
are ath9k specific.

- Felix

Re: [PATCH] ath9k: make use of slot time macros

[John W. Linville]

On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
> On 2011-02-11 5:15 PM, John W. Linville wrote:
> > On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
> >> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
> >> > From: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
> >> > 
> >> > Instead of using raw numbers to assign slot time it would be better to
> >> > make use of predefined slot time macros
> >> How does this make it better?
> > 
> > Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
> Well, neither the unit of this variable, nor the values that can be used
> are ath9k specific.

True -- the patch is probably an unnecessarily zealous attempt to avoid
"magic numbers" in the code. :-)

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

Re: [PATCH] ath9k: make use of slot time macros

[Mohammed Shafi]

On Friday 11 February 2011 06:22 PM, Felix Fietkau wrote:
> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>    
>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>
>> Instead of using raw numbers to assign slot time it would be better to
>> make use of predefined slot time macros
>>      
> How does this make it better?
>    
There is a macro already available, so why not make use of it and 
improve the readability of the code. Please correct me if I am wrong.
> - Felix
> .
>
>    

Re: [PATCH] ath9k: make use of slot time macros

[Mohammed Shafi]

On Friday 11 February 2011 09:45 PM, John W. Linville wrote:
> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>    
>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>      
>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>
>>> Instead of using raw numbers to assign slot time it would be better to
>>> make use of predefined slot time macros
>>>        
>> How does this make it better?
>>      
> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>    
John I never thought of that, but we have three macros in the driver :

mac.h             72 #define ATH9K_SLOT_TIME_6 6
mac.h             73 #define ATH9K_SLOT_TIME_9 9
mac.h             74 #define ATH9K_SLOT_TIME_20 20

both slot times 6,9 can be classified as short

thanks,
shafi

Re: [PATCH] ath9k: make use of slot time macros

[Mohammed Shafi]

On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
> On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
>    
>> On 2011-02-11 5:15 PM, John W. Linville wrote:
>>      
>>> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>>>        
>>>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>>>          
>>>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>>>
>>>>> Instead of using raw numbers to assign slot time it would be better to
>>>>> make use of predefined slot time macros
>>>>>            
>>>> How does this make it better?
>>>>          
>>> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>>>        
>> Well, neither the unit of this variable, nor the values that can be used
>> are ath9k specific.
>>      
> True -- the patch is probably an unnecessarily zealous attempt to avoid
> "magic numbers" in the code. :-)
>    
John there are two instances where these macros are used:

htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
  init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;


> John
>    

Re: [PATCH] ath9k: make use of slot time macros

[Mohammed Shafi]

On Monday 14 February 2011 10:11 AM, Mohammed Shafi wrote:
> On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
>> On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
>>> On 2011-02-11 5:15 PM, John W. Linville wrote:
>>>> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>>>>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>>>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>>>>
>>>>>> Instead of using raw numbers to assign slot time it would be 
>>>>>> better to
>>>>>> make use of predefined slot time macros
>>>>> How does this make it better?
>>>> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>>> Well, neither the unit of this variable, nor the values that can be 
>>> used
>>> are ath9k specific.
Felix  then I don't know why these macros are used here and I followed 
the same thing:

htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;
>> True -- the patch is probably an unnecessarily zealous attempt to avoid
>> "magic numbers" in the code. :-)
> John there are two instances where these macros are used:
>
> htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
>  init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;
>
>
>> John

Re: [PATCH] ath9k: make use of slot time macros

[Felix Fietkau]

On 2011-02-14 5:46 AM, Mohammed Shafi wrote:
> On Monday 14 February 2011 10:11 AM, Mohammed Shafi wrote:
>> On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
>>> On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
>>>> On 2011-02-11 5:15 PM, John W. Linville wrote:
>>>>> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>>>>>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>>>>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>>>>>
>>>>>>> Instead of using raw numbers to assign slot time it would be 
>>>>>>> better to
>>>>>>> make use of predefined slot time macros
>>>>>> How does this make it better?
>>>>> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>>>> Well, neither the unit of this variable, nor the values that can be 
>>>> used
>>>> are ath9k specific.
> Felix  then I don't know why these macros are used here and I followed 
> the same thing:
> 
> htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
> init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;
Just because the macros are there doesn't mean that it was a good idea
to use them. As far as I know, these were simply inherited from the
Atheros codebase that ath9k was based on.
I actually consider the code more readable without the redundant
"ATH9K_SLOT_TIME_" part.

- Felix

Re: [PATCH] ath9k: make use of slot time macros

[Mohammed Shafi]

On Monday 14 February 2011 07:18 PM, Felix Fietkau wrote:
> On 2011-02-14 5:46 AM, Mohammed Shafi wrote:
>    
>> On Monday 14 February 2011 10:11 AM, Mohammed Shafi wrote:
>>      
>>> On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
>>>        
>>>> On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
>>>>          
>>>>> On 2011-02-11 5:15 PM, John W. Linville wrote:
>>>>>            
>>>>>> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>>>>>>              
>>>>>>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>>>>>>                
>>>>>>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>>>>>>
>>>>>>>> Instead of using raw numbers to assign slot time it would be
>>>>>>>> better to
>>>>>>>> make use of predefined slot time macros
>>>>>>>>                  
>>>>>>> How does this make it better?
>>>>>>>                
>>>>>> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>>>>>>              
>>>>> Well, neither the unit of this variable, nor the values that can be
>>>>> used
>>>>> are ath9k specific.
>>>>>            
>> Felix  then I don't know why these macros are used here and I followed
>> the same thing:
>>
>> htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
>> init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;
>>      
> Just because the macros are there doesn't mean that it was a good idea
> to use them. As far as I know, these were simply inherited from the
> Atheros codebase that ath9k was based on.
> I actually consider the code more readable without the redundant
> "ATH9K_SLOT_TIME_" part.
>    
Felix I agree the first part, but I could still see no harm in using 
these macros.
Initially we  using these values 6,9,20(no other values) for the slot 
time and there are macros defined for them. If we are using some other 
values I would agree that its wrong.
Why not make use of it ?
IMHO if we use these macros it will at least people who are reading the 
code there are three standard values 6,9 and 20
I am sure it would help us to debug issues easily(just like Fair beacon 
distribution thing).

> - Felix
> .
>
>    

Re: [PATCH] ath9k: make use of slot time macros

[Felix Fietkau]

On 2011-02-14 3:02 PM, Mohammed Shafi wrote:
> On Monday 14 February 2011 07:18 PM, Felix Fietkau wrote:
>> On 2011-02-14 5:46 AM, Mohammed Shafi wrote:
>>    
>>> On Monday 14 February 2011 10:11 AM, Mohammed Shafi wrote:
>>>      
>>>> On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
>>>>        
>>>>> On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
>>>>>          
>>>>>> On 2011-02-11 5:15 PM, John W. Linville wrote:
>>>>>>            
>>>>>>> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>>>>>>>              
>>>>>>>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>>>>>>>                
>>>>>>>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>>>>>>>
>>>>>>>>> Instead of using raw numbers to assign slot time it would be
>>>>>>>>> better to
>>>>>>>>> make use of predefined slot time macros
>>>>>>>>>                  
>>>>>>>> How does this make it better?
>>>>>>>>                
>>>>>>> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>>>>>>>              
>>>>>> Well, neither the unit of this variable, nor the values that can be
>>>>>> used
>>>>>> are ath9k specific.
>>>>>>            
>>> Felix  then I don't know why these macros are used here and I followed
>>> the same thing:
>>>
>>> htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
>>> init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;
>>>      
>> Just because the macros are there doesn't mean that it was a good idea
>> to use them. As far as I know, these were simply inherited from the
>> Atheros codebase that ath9k was based on.
>> I actually consider the code more readable without the redundant
>> "ATH9K_SLOT_TIME_" part.
>>    
> Felix I agree the first part, but I could still see no harm in using 
> these macros.
> Initially we  using these values 6,9,20(no other values) for the slot 
> time and there are macros defined for them. If we are using some other 
> values I would agree that its wrong.
> Why not make use of it ?
> IMHO if we use these macros it will at least people who are reading the 
> code there are three standard values 6,9 and 20
How is 6 a standard value? And why use driver specific defines when it's
really an 802.11 standard thing?

Using something like this would make the code more readable:
#define IEEE80211_SHORT_SLOT_TIME	9
#define IEEE80211_LONG_SLOT_TIME	20

ATH9K_SLOT_TIME_9 or ATH9K_SLOT_TIME_20? Not so much...

> I am sure it would help us to debug issues easily(just like Fair beacon 
> distribution thing).
I really don't see how this is helpful in any way.
The main reason why I object to stuff like this is because I think that
"other code is like that" is not a good reason for repeating it,
especially if what was done on the other code never made much sense to
begin with. In this case I think it's more of a reason to clean up the
other code first and then make things more consistent :)

- Felix

Re: [PATCH] ath9k: make use of slot time macros

[Mohammed Shafi]

On Monday 14 February 2011 07:59 PM, Felix Fietkau wrote:
> On 2011-02-14 3:02 PM, Mohammed Shafi wrote:
>    
>> On Monday 14 February 2011 07:18 PM, Felix Fietkau wrote:
>>      
>>> On 2011-02-14 5:46 AM, Mohammed Shafi wrote:
>>>
>>>        
>>>> On Monday 14 February 2011 10:11 AM, Mohammed Shafi wrote:
>>>>
>>>>          
>>>>> On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
>>>>>
>>>>>            
>>>>>> On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
>>>>>>
>>>>>>              
>>>>>>> On 2011-02-11 5:15 PM, John W. Linville wrote:
>>>>>>>
>>>>>>>                
>>>>>>>> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>>>>>>>>
>>>>>>>>                  
>>>>>>>>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>>>>>>>>
>>>>>>>>>                    
>>>>>>>>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>>>>>>>>
>>>>>>>>>> Instead of using raw numbers to assign slot time it would be
>>>>>>>>>> better to
>>>>>>>>>> make use of predefined slot time macros
>>>>>>>>>>
>>>>>>>>>>                      
>>>>>>>>> How does this make it better?
>>>>>>>>>
>>>>>>>>>                    
>>>>>>>> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>>>>>>>>
>>>>>>>>                  
>>>>>>> Well, neither the unit of this variable, nor the values that can be
>>>>>>> used
>>>>>>> are ath9k specific.
>>>>>>>
>>>>>>>                
>>>> Felix  then I don't know why these macros are used here and I followed
>>>> the same thing:
>>>>
>>>> htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
>>>> init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;
>>>>
>>>>          
>>> Just because the macros are there doesn't mean that it was a good idea
>>> to use them. As far as I know, these were simply inherited from the
>>> Atheros codebase that ath9k was based on.
>>> I actually consider the code more readable without the redundant
>>> "ATH9K_SLOT_TIME_" part.
>>>
>>>        
>> Felix I agree the first part, but I could still see no harm in using
>> these macros.
>> Initially we  using these values 6,9,20(no other values) for the slot
>> time and there are macros defined for them. If we are using some other
>> values I would agree that its wrong.
>> Why not make use of it ?
>> IMHO if we use these macros it will at least people who are reading the
>> code there are three standard values 6,9 and 20
>>      
> How is 6 a standard value? And why use driver specific defines when it's
> really an 802.11 standard thing?
>
> Using something like this would make the code more readable:
> #define IEEE80211_SHORT_SLOT_TIME	9
> #define IEEE80211_LONG_SLOT_TIME	20
>
> ATH9K_SLOT_TIME_9 or ATH9K_SLOT_TIME_20? Not so much...
>
>    
>> I am sure it would help us to debug issues easily(just like Fair beacon
>> distribution thing).
>>      
> I really don't see how this is helpful in any way.
> The main reason why I object to stuff like this is because I think that
> "other code is like that" is not a good reason for repeating it,
> especially if what was done on the other code never made much sense to
> begin with. In this case I think it's more of a reason to clean up the
> other code first and then make things more consistent :)
>    
Felix, I did not send the patch by looking at the other code :), its 
just only a part of justification.
Any way I have no problems if I this patch does not gets merged as it is 
not going to fix any thing.
I am still not yet convinced why its wrong, but I do respect your views 
and really thanks a lot for your reviews
> - Felix
> .
>
>    

Re: [PATCH] ath9k: make use of slot time macros

[John W. Linville]

On Mon, Feb 14, 2011 at 10:11:01AM +0530, Mohammed Shafi wrote:
> On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
> >On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
> >>On 2011-02-11 5:15 PM, John W. Linville wrote:
> >>>On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
> >>>>On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
> >>>>>From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
> >>>>>
> >>>>>Instead of using raw numbers to assign slot time it would be better to
> >>>>>make use of predefined slot time macros
> >>>>How does this make it better?
> >>>Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
> >>Well, neither the unit of this variable, nor the values that can be used
> >>are ath9k specific.
> >True -- the patch is probably an unnecessarily zealous attempt to avoid
> >"magic numbers" in the code. :-)
> John there are two instances where these macros are used:
> 
> htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
>  init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;

Maybe you should just get rid of those instead?

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

Re: [PATCH] ath9k: make use of slot time macros

[Mohammed Shafi]

On Tuesday 15 February 2011 01:44 AM, John W. Linville wrote:
> On Mon, Feb 14, 2011 at 10:11:01AM +0530, Mohammed Shafi wrote:
>    
>> On Friday 11 February 2011 09:59 PM, John W. Linville wrote:
>>      
>>> On Fri, Feb 11, 2011 at 05:21:06PM +0100, Felix Fietkau wrote:
>>>        
>>>> On 2011-02-11 5:15 PM, John W. Linville wrote:
>>>>          
>>>>> On Fri, Feb 11, 2011 at 01:52:23PM +0100, Felix Fietkau wrote:
>>>>>            
>>>>>> On 2011-02-11 8:01 AM, Mohammed Shafi Shajakhan wrote:
>>>>>>              
>>>>>>> From: Mohammed Shafi Shajakhan<mshajakhan@atheros.com>
>>>>>>>
>>>>>>> Instead of using raw numbers to assign slot time it would be better to
>>>>>>> make use of predefined slot time macros
>>>>>>>                
>>>>>> How does this make it better?
>>>>>>              
>>>>> Maybe if it was ATH9K_SHORT_SLOT_TIME it would make more sense?
>>>>>            
>>>> Well, neither the unit of this variable, nor the values that can be used
>>>> are ath9k specific.
>>>>          
>>> True -- the patch is probably an unnecessarily zealous attempt to avoid
>>> "magic numbers" in the code. :-)
>>>        
>> John there are two instances where these macros are used:
>>
>> htc_drv_beacon.c 242 if (ah->slottime == ATH9K_SLOT_TIME_20)
>>   init.c           517 sc->beacon.slottime = ATH9K_SLOT_TIME_9;
>>      
> Maybe you should just get rid of those instead?
>    
Ok John, thanks.