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From:   Kalle Valo <kvalo@codeaurora.org>
To:     Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc:     Christian Lamparter <chunkeey@gmail.com>,
        Lee Jones <lee.jones@linaro.org>, davem@davemloft.net,
        kuba@kernel.org, linux-kernel@vger.kernel.org,
        Christian Lamparter <chunkeey@googlemail.com>,
        Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 08/30] net: wireless: ath: carl9170: Mark 'ar9170_qmap' as __maybe_unused
References: <20200814113933.1903438-1-lee.jones@linaro.org>
        <20200814113933.1903438-9-lee.jones@linaro.org>
        <7ef231f2-e6d3-904f-dc3a-7ef82beda6ef@gmail.com>
        <9776eb47-6b83-a891-f057-dd34d14ea16e@rasmusvillemoes.dk>
Date:   Mon, 17 Aug 2020 15:59:47 +0300
In-Reply-To: <9776eb47-6b83-a891-f057-dd34d14ea16e@rasmusvillemoes.dk> (Rasmus
        Villemoes's message of "Mon, 17 Aug 2020 10:26:16 +0200")
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Rasmus Villemoes <linux@rasmusvillemoes.dk> writes:

> On 14/08/2020 17.14, Christian Lamparter wrote:
>> On 2020-08-14 13:39, Lee Jones wrote:
>>> 'ar9170_qmap' is used in some source files which include carl9170.h,
>>> but not all of them.=C2=A0 Mark it as __maybe_unused to show that this =
is
>>> not only okay, it's expected.
>>>
>>> Fixes the following W=3D1 kernel build warning(s)
>>=20
>> Is this W=3D1 really a "must" requirement? I find it strange having
>> __maybe_unused in header files as this "suggests" that the
>> definition is redundant.
>
> In this case it seems one could replace the table lookup with a
>
> static inline u8 ar9170_qmap(u8 idx) { return 3 - idx; }
>
> gcc doesn't warn about unused static inline functions (or one would have
> a million warnings to deal with). Just my $0.02.

Yeah, this is much better.

And I think that static variables should not even be in the header
files. Doesn't it mean that there's a local copy of the variable
everytime the .h file is included? Sure, in this case the overhead is
small (4 bytes per include) but still it's wrong. Having a static inline
function would solve that problem as well the compiler warning.

--=20
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatc=
hes