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

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Message-Id: <20180921202130.12480-1-natechancellor@gmail.com>
Date:   Fri, 21 Sep 2018 13:21:31 -0700
From:   Nathan Chancellor <natechancellor@...il.com>
To:     Lee Jones <lee.jones@...aro.org>,
        Daniel Thompson <daniel.thompson@...aro.org>,
        Jingoo Han <jingoohan1@...il.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Cc:     dri-devel@...ts.freedesktop.org, linux-fbdev@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Nathan Chancellor <natechancellor@...il.com>
Subject: [PATCH] backlight: lm3639: Unconditionally call led_classdev_unregister

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(-)

diff --git a/drivers/video/backlight/lm3639_bl.c b/drivers/video/backlight/lm3639_bl.c
index cd50df5807ea..086611c7bc03 100644
--- a/drivers/video/backlight/lm3639_bl.c
+++ b/drivers/video/backlight/lm3639_bl.c
@@ -400,10 +400,8 @@ static int lm3639_remove(struct i2c_client *client)
 
 	regmap_write(pchip->regmap, REG_ENABLE, 0x00);
 
-	if (&pchip->cdev_torch)
-		led_classdev_unregister(&pchip->cdev_torch);
-	if (&pchip->cdev_flash)
-		led_classdev_unregister(&pchip->cdev_flash);
+	led_classdev_unregister(&pchip->cdev_torch);
+	led_classdev_unregister(&pchip->cdev_flash);
 	if (pchip->bled)
 		device_remove_file(&(pchip->bled->dev), &dev_attr_bled_mode);
 	return 0;
-- 
2.19.0