[PATCH] video: backlight: adp8870: Fix warn_unused_result warning reported by Stephen Rothwell

[PATCH] video: backlight: adp8870: Fix warn_unused_result warning reported by Stephen Rothwell

[michael.hennerich]

From: Michael Hennerich <michael.hennerich@analog.com>

handle return value, strict_strtoul is declared with attribute warn_unused_result

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
---
 drivers/video/backlight/adp8860_bl.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/video/backlight/adp8860_bl.c b/drivers/video/backlight/adp8860_bl.c
index 3ec2460..8746303 100644
--- a/drivers/video/backlight/adp8860_bl.c
+++ b/drivers/video/backlight/adp8860_bl.c
@@ -502,8 +502,10 @@ static ssize_t adp8860_bl_l1_daylight_max_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct adp8860_bl *data = dev_get_drvdata(dev);
+	int ret = strict_strtoul(buf, 10, &data->cached_daylight_max);
+	if (ret)
+		return ret;
 
-	strict_strtoul(buf, 10, &data->cached_daylight_max);
 	return adp8860_store(dev, buf, count, ADP8860_BLMX1);
 }
 static DEVICE_ATTR(l1_daylight_max, 0664, adp8860_bl_l1_daylight_max_show,
-- 
1.6.0.2

Re: [PATCH] video: backlight: adp8870: Fix warn_unused_result warning reported by Stephen Rothwell

[Andrew Morton]

I have some bones to gnaw.  Not specific to this patch ;)

On Fri, 29 Oct 2010 16:54:26 +0200
<michael.hennerich@analog.com> wrote:

> Subject: [PATCH] video: backlight: adp8870: Fix warn_unused_result warning reported by Stephen Rothwell

Lots of people are doing this "video: backlight: adp8870:" thing
lately.  And it's good, but why not just use
"drivers/video/backlight/adp8860_bl.c" to identify the affected
susbsytem/file/etc?  It's simple and uniform.  It's not always the
appropriate thing to do, but replacing the /'s with ": " seems rather
random and pointless.

Secondly, no, the point of this patch is not to fix a
warn_unused_result() warning!  The patch actually fixes a bug: the code
wasn't checking the strict_strtoul() return value.  The warning is
simply what alerted us to the bug.

So I renamed this patch to

	drivers/video/backlight/adp8860_bl.c: check strict_strtoul() return value

Re: [Device-drivers-devel] [PATCH] video: backlight: adp8870: Fix warn_unused_result warning reported by Stephen Rothwell

[Mike Frysinger]

On Fri, Oct 29, 2010 at 15:25, Andrew Morton wrote:
>> Subject: [PATCH] video: backlight: adp8870: Fix warn_unused_result warning reported by Stephen Rothwell
>
> Lots of people are doing this "video: backlight: adp8870:" thing
> lately.  And it's good, but why not just use
> "drivers/video/backlight/adp8860_bl.c" to identify the affected
> susbsytem/file/etc?  It's simple and uniform.  It's not always the
> appropriate thing to do, but replacing the /'s with ": " seems rather
> random and pointless.

the colons and spaces make it a lot easier to pick out in a git log.
your suggestion makes it much harder to read due to the lack of
whitespace.
-mike

RE: [PATCH] video: backlight: adp8870: Fix warn_unused_result warning reported by Stephen Rothwell

[Hennerich, Michael]

Andrew Morton wrote on 2010-10-29:
>
> I have some bones to gnaw.  Not specific to this patch ;)
>
> On Fri, 29 Oct 2010 16:54:26 +0200
> <michael.hennerich@analog.com> wrote:
>
>> Subject: [PATCH] video: backlight: adp8870: Fix warn_unused_result
>> warning reported by Stephen Rothwell
>
> Lots of people are doing this "video: backlight: adp8870:" thing
> lately.  And it's good, but why not just use
> "drivers/video/backlight/adp8860_bl.c" to identify the affected
> susbsytem/file/etc?  It's simple and uniform.  It's not always the
> appropriate thing to do, but replacing the /'s with ": " seems rather
> random and pointless.

Think it's easier to read, or better skip reading further.

> Secondly, no, the point of this patch is not to fix a
> warn_unused_result() warning!  The patch actually fixes a bug: the
> code wasn't checking the strict_strtoul() return value.  The warning
> is simply what alerted us to the bug.
>
> So I renamed this patch to
>
>       drivers/video/backlight/adp8860_bl.c: check strict_strtoul() return
> value

Agreed - Thanks for fixing it.

Greetings,
Michael

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