Subject: Re: [PATCH 1/2 RFC] ath10k: move code out of the parameter list

From: Nicholas Mc Guire <[email-masked]>
Date: Wed, 11 Mar 2015 19:13:12 +0100

On Wed, 11 Mar 2015, Pat Erley wrote:

> On 03/11/2015 12:19 PM, Nicholas Mc Guire wrote:
>> Putting code into the parameter list of wait_event_timeout() might be
>> legal C-code but not really readable - the "inline" code is simply
>> moved into a function and that passed to wait_event_timeout() as the
>> condition.
>>
>> Signed-off-by: Nicholas Mc Guire <[email-masked]>
>> ---
>>
>> Thanks to Bjorn Mork <[email-masked]> for clarifying my initial confusion !
>>
>> Patch was only compile tested with x86_64_defconfig + CONFIG_ATH_CARDS=m,
>> CONFIG_ATH10K=m
>>
>> Patch is against 4.0-rc3 (localversion-next is -next-20150311)
>>
>>   drivers/net/wireless/ath/ath10k/mac.c |   32 ++++++++++++++++++--------------
>>   1 file changed, 18 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
>> index e8cc19f..7b27d99 100644
>> --- a/drivers/net/wireless/ath/ath10k/mac.c
>> +++ b/drivers/net/wireless/ath/ath10k/mac.c
>> @@ -4463,11 +4463,25 @@ static int ath10k_set_rts_threshold(struct ieee80211_hw *hw, u32 value)
>>   	return ret;
>>   }
>>
>> +static bool check_htt_state(struct ath10k *ar, bool skip)
>> +{
>> +	bool empty;
>> +
>> +	spin_lock_bh(&ar->htt.tx_lock);
>> +	empty = (ar->htt.num_pending_tx == 0);
>> +	spin_unlock_bh(&ar->htt.tx_lock);
>> +
>> +	skip = (ar->state == ATH10K_STATE_WEDGED) ||
>> +		test_bit(ATH10K_FLAG_CRASH_FLUSH,
>> +			 &ar->dev_flags);
>> +	return (empty || skip);
>> +}
>> +
>>   static void ath10k_flush(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
>>   			 u32 queues, bool drop)
>>   {
>>   	struct ath10k *ar = hw->priv;
>> -	bool skip;
>> +	bool skip = false;
>>   	int ret;
>>
>>   	/* mac80211 doesn't care if we really xmit queued frames or not
>> @@ -4480,19 +4494,9 @@ static void ath10k_flush(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
>>   	if (ar->state == ATH10K_STATE_WEDGED)
>>   		goto skip;
>>
>> -	ret = wait_event_timeout(ar->htt.empty_tx_wq, ({
>> -			bool empty;
>> -
>> -			spin_lock_bh(&ar->htt.tx_lock);
>> -			empty = (ar->htt.num_pending_tx == 0);
>> -			spin_unlock_bh(&ar->htt.tx_lock);
>> -
>> -			skip = (ar->state == ATH10K_STATE_WEDGED) ||
>> -			       test_bit(ATH10K_FLAG_CRASH_FLUSH,
>> -					&ar->dev_flags);
>> -
>> -			(empty || skip);
>> -		}), ATH10K_FLUSH_TIMEOUT_HZ);
>> +	ret = wait_event_timeout(ar->htt.empty_tx_wq,
>> +				 check_htt_state(ar, skip),
>> +				 ATH10K_FLUSH_TIMEOUT_HZ);
>>
>>   	if (ret <= 0 || skip)
>>   		ath10k_warn(ar, "failed to flush transmit queue (skip %i ar-state %i): %i\n",
>>
>
> Doesn't this change not assign to 'skip' in the calling function?  So  
> you'd want to make it:
>
> static bool check_htt_state(struct ath10k *ar, bool *skip)
> {
> 	bool empty;
>
> 	spin_lock_bh(&ar->htt.tx_lock);
> 	empty = (ar->htt.num_pending_tx == 0);
> 	spin_unlock_bh(&ar->htt.tx_lock);
>
> 	*skip = (ar->state == ATH10K_STATE_WEDGED) ||
> 		test_bit(ATH10K_FLAG_CRASH_FLUSH,
> 			 &ar->dev_flags);
> 	return (empty || *skip);
> }
>
> ret = wait_event_timeout(ar->htt.empty_tx_wq,
> 				 check_htt_state(ar, &skip),
> 				 ATH10K_FLUSH_TIMEOUT_HZ);
>
> To preserve the previous behavior?

yup - thats a bit braindead on my side - as skip is used later to evaluate 
the status call by value is buggy here. Will fix that up once I know if
the principle approach to this cleanup is ok.

thx!
hofrat