Re: [PATCH] gpio: arizona: put pm_runtime in case of failure

Re: [PATCH] gpio: arizona: put pm_runtime in case of failure

[Markus Elfring]

I recommend to replace the word “pm_runtime” by the
alternative “PM run time system” in the patch subject.


> Calling pm_runtime_get_sync increments the counter even in case of
> failure, causing incorrect ref count if pm_runtime_put is not called in
> error handling paths.

Should the term “reference count” be used here?


> Call pm_runtime_put if pm_runtime_get_sync fails.

The diff hunks show an other function name.


…
> +++ b/drivers/gpio/gpio-arizona.c
> @@ -64,6 +64,7 @@  static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
>  		ret = pm_runtime_get_sync(chip->parent);
>  		if (ret < 0) {
>  			dev_err(chip->parent, "Failed to resume: %d\n", ret);
> +			pm_runtime_put_autosuspend(chip->parent);
>  			return ret;
>  		}

You propose to use identical statements in three if branches.
Please add a corresponding jump target for better exception handling.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=435faf5c218a47fd6258187f62d9bb1009717896#n455


Would you like to add the tag “Fixes” to the commit message?


I find it amazing how many questionable implementation details
you pointed out recently.
Were these contributions triggered by an evolving source code analysis
tool like CheQ?
https://github.com/umnsec/cheq/

Regards,
Markus

Re: [PATCH] gpio: arizona: put pm_runtime in case of failure

[Greg KH]

On Fri, Jun 05, 2020 at 02:14:38PM +0200, Markus Elfring wrote:
> I recommend to replace the word “pm_runtime” by the
> alternative “PM run time system” in the patch subject.
> 
> 
> > Calling pm_runtime_get_sync increments the counter even in case of
> > failure, causing incorrect ref count if pm_runtime_put is not called in
> > error handling paths.
> 
> Should the term “reference count” be used here?
> 
> 
> > Call pm_runtime_put if pm_runtime_get_sync fails.
> 
> The diff hunks show an other function name.
> 
> 
> …
> > +++ b/drivers/gpio/gpio-arizona.c
> > @@ -64,6 +64,7 @@  static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
> >  		ret = pm_runtime_get_sync(chip->parent);
> >  		if (ret < 0) {
> >  			dev_err(chip->parent, "Failed to resume: %d\n", ret);
> > +			pm_runtime_put_autosuspend(chip->parent);
> >  			return ret;
> >  		}
> 
> You propose to use identical statements in three if branches.
> Please add a corresponding jump target for better exception handling.
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=435faf5c218a47fd6258187f62d9bb1009717896#n455
> 
> 
> Would you like to add the tag “Fixes” to the commit message?
> 
> 
> I find it amazing how many questionable implementation details
> you pointed out recently.
> Were these contributions triggered by an evolving source code analysis
> tool like CheQ?
> https://github.com/umnsec/cheq/
> 
> Regards,
> Markus

Hi,

This is the semi-friendly patch-bot of Greg Kroah-Hartman.

Markus, you seem to have sent a nonsensical or otherwise pointless
review comment to a patch submission on a Linux kernel developer mailing
list.  I strongly suggest that you not do this anymore.  Please do not
bother developers who are actively working to produce patches and
features with comments that, in the end, are a waste of time.

Patch submitter, please ignore Markus's suggestion; you do not need to
follow it at all.  The person/bot/AI that sent it is being ignored by
almost all Linux kernel maintainers for having a persistent pattern of
behavior of producing distracting and pointless commentary, and
inability to adapt to feedback.  Please feel free to also ignore emails
from them.

thanks,

greg k-h's patch email bot

[PATCH] gpio: arizona: put pm_runtime in case of failure

[Navid Emamdoost]

Calling pm_runtime_get_sync increments the counter even in case of
failure, causing incorrect ref count if pm_runtime_put is not called in
error handling paths. Call pm_runtime_put if pm_runtime_get_sync fails.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
---
 drivers/gpio/gpio-arizona.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-arizona.c b/drivers/gpio/gpio-arizona.c
index 7520a13b4c7c..5bda38e0780f 100644
--- a/drivers/gpio/gpio-arizona.c
+++ b/drivers/gpio/gpio-arizona.c
@@ -64,6 +64,7 @@ static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
 		ret = pm_runtime_get_sync(chip->parent);
 		if (ret < 0) {
 			dev_err(chip->parent, "Failed to resume: %d\n", ret);
+			pm_runtime_put_autosuspend(chip->parent);
 			return ret;
 		}
 
@@ -72,12 +73,15 @@ static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
 		if (ret < 0) {
 			dev_err(chip->parent, "Failed to drop cache: %d\n",
 				ret);
+			pm_runtime_put_autosuspend(chip->parent);
 			return ret;
 		}
 
 		ret = regmap_read(arizona->regmap, reg, &val);
-		if (ret < 0)
+		if (ret < 0) {
+			pm_runtime_put_autosuspend(chip->parent);
 			return ret;
+		}
 
 		pm_runtime_mark_last_busy(chip->parent);
 		pm_runtime_put_autosuspend(chip->parent);
-- 
2.17.1

Re: [PATCH] gpio: arizona: put pm_runtime in case of failure

[Charles Keepax]

On Thu, Jun 04, 2020 at 10:00:52PM -0500, Navid Emamdoost wrote:
> Calling pm_runtime_get_sync increments the counter even in case of
> failure, causing incorrect ref count if pm_runtime_put is not called in
> error handling paths. Call pm_runtime_put if pm_runtime_get_sync fails.
> 
> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> ---

Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Thanks,
Charles

Re: [PATCH] gpio: arizona: put pm_runtime in case of failure

[Linus Walleij]

On Fri, Jun 5, 2020 at 5:01 AM Navid Emamdoost
<navid.emamdoost@gmail.com> wrote:

> Calling pm_runtime_get_sync increments the counter even in case of
> failure, causing incorrect ref count if pm_runtime_put is not called in
> error handling paths. Call pm_runtime_put if pm_runtime_get_sync fails.
>
> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>

Patch applied for fixes.

Yours,
Linus Walleij