linux-kernel - Re: [PATCH 1/4] staging: r8188eu: refactor rtw_is_cckrates

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Message-ID: <5ec326711eaf178754a02816f20510a7d860b378.camel@perches.com>
Date:   Mon, 16 Aug 2021 04:14:31 -0700
From:   Joe Perches <joe@...ches.com>
To:     Michael Straube <straube.linux@...il.com>,
        gregkh@...uxfoundation.org
Cc:     Larry.Finger@...inger.net, phil@...lpotter.co.uk, martin@...ser.cx,
        fmdefrancesco@...il.com, linux-staging@...ts.linux.dev,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/4] staging: r8188eu: refactor
 rtw_is_cckrates_included()

On Mon, 2021-08-16 at 11:58 +0200, Michael Straube wrote:
> Refactor function rtw_is_cckrates_included(). Improves readability
> and slightly reduces object file size.
[]
> diff --git a/drivers/staging/r8188eu/core/rtw_ieee80211.c b/drivers/staging/r8188eu/core/rtw_ieee80211.c
[]
> @@ -70,13 +70,12 @@ int rtw_get_bit_value_from_ieee_value(u8 val)
>  
> 
>  uint	rtw_is_cckrates_included(u8 *rate)
>  {
> -	u32	i = 0;
> +	while (*rate) {
> +		u8 r = *rate & 0x7f;
> 
> -	while (rate[i] != 0) {
> -		if  ((((rate[i]) & 0x7f) == 2) || (((rate[i]) & 0x7f) == 4) ||
> -		     (((rate[i]) & 0x7f) == 11)  || (((rate[i]) & 0x7f) == 22))
> +		if (r == 2 || r == 4 || r == 11 || r == 22)
>  			return true;
> -		i++;
> +		rate++;
>  	}
>  	return false;
>  }

Bikeshed:

More compact code with only 1 reference of rate not 3 is more
readable to at least me.

	u8 r;

	while ((r = *rate++ & 0x7f)) {
		if (r == 2 || r == 4 || r == 11 || r == 22)
			return true;
	}

	return false;

And you might make a static inline for the test of r so it could
be reused in the rtw_is_cckratesonly_included function

static inline bool is_cckrate(u8 rate)
{
	return rate == 2 || rate == 4 || rate == 11 || rate == 22;
}

so this could be:

	u8 r;

	while ((r = *rate++ & 0x7f)) {
		if (is_cckrate(r))
			return true;
	}

	return false;