[PATCH] misc: bh1770glc: Use common error handling code in bh1770_power_state_store()

[PATCH] misc: bh1770glc: Use common error handling code in bh1770_power_state_store()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Fri, 27 Oct 2017 18:00:31 +0200

Adjust jump targets so that a bit of exception handling can be better
reused in an if branch of this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/misc/bh1770glc.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/misc/bh1770glc.c b/drivers/misc/bh1770glc.c
index 9c62bf064f77..c4c108ed88b0 100644
--- a/drivers/misc/bh1770glc.c
+++ b/drivers/misc/bh1770glc.c
@@ -660,15 +660,14 @@ static ssize_t bh1770_power_state_store(struct device *dev,
 		pm_runtime_get_sync(dev);
 
 		ret = bh1770_lux_rate(chip, chip->lux_rate_index);
-		if (ret < 0) {
-			pm_runtime_put(dev);
-			goto leave;
-		}
+		if (ret < 0)
+			goto put_runtime;
 
 		ret = bh1770_lux_interrupt_control(chip, BH1770_ENABLE);
 		if (ret < 0) {
+put_runtime:
 			pm_runtime_put(dev);
-			goto leave;
+			goto unlock;
 		}
 
 		/* This causes interrupt after the next measurement cycle */
@@ -681,7 +680,7 @@ static ssize_t bh1770_power_state_store(struct device *dev,
 		pm_runtime_put(dev);
 	}
 	ret = count;
-leave:
+unlock:
 	mutex_unlock(&chip->mutex);
 	return ret;
 }
-- 
2.14.3

Re: [PATCH] misc: bh1770glc: Use common error handling code in bh1770_power_state_store()

[Daniele Nicolodi]

On 10/27/17 10:20 AM, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Fri, 27 Oct 2017 18:00:31 +0200
> 
> Adjust jump targets so that a bit of exception handling can be better
> reused in an if branch of this function.

What is the benefit brought by this change?

Anyhow, are you seriously suggesting adding a goto to a label define
within a if block?  Is this somehow an Halloween related joke?


> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  drivers/misc/bh1770glc.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/misc/bh1770glc.c b/drivers/misc/bh1770glc.c
> index 9c62bf064f77..c4c108ed88b0 100644
> --- a/drivers/misc/bh1770glc.c
> +++ b/drivers/misc/bh1770glc.c
> @@ -660,15 +660,14 @@ static ssize_t bh1770_power_state_store(struct device *dev,
>  		pm_runtime_get_sync(dev);
>  
>  		ret = bh1770_lux_rate(chip, chip->lux_rate_index);
> -		if (ret < 0) {
> -			pm_runtime_put(dev);
> -			goto leave;
> -		}
> +		if (ret < 0)
> +			goto put_runtime;
>  
>  		ret = bh1770_lux_interrupt_control(chip, BH1770_ENABLE);
>  		if (ret < 0) {
> +put_runtime:
>  			pm_runtime_put(dev);
> -			goto leave;
> +			goto unlock;
>  		}
>  
>  		/* This causes interrupt after the next measurement cycle */
> @@ -681,7 +680,7 @@ static ssize_t bh1770_power_state_store(struct device *dev,
>  		pm_runtime_put(dev);
>  	}
>  	ret = count;
> -leave:
> +unlock:
>  	mutex_unlock(&chip->mutex);
>  	return ret;
>  }
> 

Re: [PATCH] misc: bh1770glc: Use common error handling code in bh1770_power_state_store()

[Greg Kroah-Hartman]

On Fri, Oct 27, 2017 at 11:11:13AM -0600, Daniele Nicolodi wrote:
> On 10/27/17 10:20 AM, SF Markus Elfring wrote:
> > From: Markus Elfring <elfring@users.sourceforge.net>
> > Date: Fri, 27 Oct 2017 18:00:31 +0200
> > 
> > Adjust jump targets so that a bit of exception handling can be better
> > reused in an if branch of this function.
> 
> What is the benefit brought by this change?

Please note, you are responding to someone who lots and lots of kernel
maintainers/developers have blacklisted, myself included.  It's just not
worth your effort, I recommend doing the same, as I'm not applying any
patches from this author, unless some other maintainer wants to take the
time to validate and send them on to me.

kill-files are a good thing, please use them :)

good luck!

greg k-h

Re: misc: bh1770glc: Use common error handling code in bh1770_power_state_store()

[SF Markus Elfring]

>> Adjust jump targets so that a bit of exception handling can be better
>> reused in an if branch of this function.
> 
> What is the benefit brought by this change?

Will you notice that the object code size can be a bit smaller
because the call of the function “pm_runtime_put” is specified at
two places in the implementation in comparison to three places before?


> Anyhow, are you seriously suggesting adding a goto to a label define
> within a if block?

Yes. - For this update suggestion.


> Is this somehow an Halloween related joke?

I hope not.

Another software design approach would be to move two statements from
the affected if branch to the end of this function. Such an adjustment
would have the consequence that the statement “goto unlock” will be
transformed into a jump to a backward target.
Would you prefer such an implementation variant instead?

Regards,
Markus