linux-kernel - Re: [PATCH] backlight: lm3639: Unconditionally call led_classdev

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Date:   Tue, 9 Oct 2018 02:10:48 -0700
From:   Lee Jones <lee.jones@...aro.org>
To:     Nathan Chancellor <natechancellor@...il.com>
Cc:     Daniel Thompson <daniel.thompson@...aro.org>,
        Jingoo Han <jingoohan1@...il.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        dri-devel@...ts.freedesktop.org, linux-fbdev@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Nick Desaulniers <ndesaulniers@...gle.com>
Subject: Re: [PATCH] backlight: lm3639: Unconditionally call
 led_classdev_unregister

On Fri, 21 Sep 2018, Nathan Chancellor wrote:

> Clang warns that the address of a pointer will always evaluated as true
> in a boolean context.
> 
> drivers/video/backlight/lm3639_bl.c:403:14: warning: address of
> 'pchip->cdev_torch' will always evaluate to 'true'
> [-Wpointer-bool-conversion]
>         if (&pchip->cdev_torch)
>         ~~   ~~~~~~~^~~~~~~~~~
> drivers/video/backlight/lm3639_bl.c:405:14: warning: address of
> 'pchip->cdev_flash' will always evaluate to 'true'
> [-Wpointer-bool-conversion]
>         if (&pchip->cdev_flash)
>         ~~   ~~~~~~~^~~~~~~~~~
> 2 warnings generated.
> 
> These statements have been present since 2012, introduced by
> commit 0f59858d5119 ("backlight: add new lm3639 backlight
> driver"). Given that they have been called unconditionally since
> then presumably without any issues, removing the always true if
> statements to fix the warnings without any real world changes.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/119
> Signed-off-by: Nathan Chancellor <natechancellor@...il.com>
> ---
> 
> Alternatively, it's possible the address wasn't supposed to be taken or
> the dev in these structs should be checked instead. I don't have this
> hardware to make that call so I would appreciate some review and
> opinions on what was intended here.
> 
> Thanks!
> 
>  drivers/video/backlight/lm3639_bl.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)

Applied, thanks.

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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