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From:   David Laight <David.Laight@ACULAB.COM>
To:     "'trix@redhat.com'" <trix@redhat.com>,
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Subject: RE: [PATCH] ath9k: initialize arrays at compile time
Thread-Topic: [PATCH] ath9k: initialize arrays at compile time
Thread-Index: AQHYPG4UGesvc0U9PEWregiQnXO486zIm6Kg
Date:   Sun, 20 Mar 2022 18:46:46 +0000
Message-ID: <d06ce4fa239645cc9de48c1062f58f14@AcuMS.aculab.com>
References: <20220320152028.2263518-1-trix@redhat.com>
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From: trix@redhat.com <trix@redhat.com>
> Sent: 20 March 2022 15:20
> 
> Early clearing of arrays with
> memset(array, 0, size);
> is equivilent to initializing the array in its decl with
> array[size] = { 0 };
> 
> Since compile time is preferred over runtime,
> convert the memsets to initializations.
...
> diff --git a/drivers/net/wireless/ath/ath9k/ar9003_calib.c
> b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
> index dc24da1ff00b1..39fcc158cb159 100644
> --- a/drivers/net/wireless/ath/ath9k/ar9003_calib.c
> +++ b/drivers/net/wireless/ath/ath9k/ar9003_calib.c
> @@ -891,10 +891,9 @@ static void ar9003_hw_tx_iq_cal_outlier_detection(struct ath_hw *ah,
>  {
>  	int i, im, nmeasurement;
>  	int magnitude, phase;
> -	u32 tx_corr_coeff[MAX_MEASUREMENT][AR9300_MAX_CHAINS];
> +	u32 tx_corr_coeff[MAX_MEASUREMENT][AR9300_MAX_CHAINS] = { 0 };

For a two dimensional array that needs to be {{0}} (or {}).
And, since there is only one definitions of 'coeff' it can
be static!
(Currently on 96 bytes - si not a real problem on-stack.)

Although I just failed to find the lock that stops
concurrent execution on multiple cpu.

	David

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