[v2,18/20] pinctrl: freescale: mxs: Fix refcount of child

Commit Message

Peng Fan (OSS) May 4, 2024, 1:20 p.m. UTC

From: Peng Fan <[e-mail]>

of_get_next_child() will increase refcount of the returned node, need
use of_node_put() on it when done.

Per current implementation, 'child' will be override by
for_each_child_of_node(np, child), so use of_get_child_count to avoid
refcount leakage.

Fixes: 17723111e64f ("pinctrl: add pinctrl-mxs support")
Signed-off-by: Peng Fan <[e-mail]>
---
 drivers/pinctrl/freescale/pinctrl-mxs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Markus Elfring May 27, 2024, 3:56 p.m. UTC | #1

How do you think about to use the summary phrase “Fix reference counting for children in mxs_pinctrl_probe_dt()”?


…
> of_get_next_child() will increase refcount …

                                    the reference counter?


> Per current implementation, 'child' will be override by

                                              overridden?


> for_each_child_of_node(np, child), so use of_get_child_count to avoid
> refcount leakage.

Another wording suggestion:
  for_each_child_of_node(np, child). Thus use an of_get_child_count() call
  to avoid reference counting leakage.


Regards,
Markus

Peng Fan May 30, 2024, 8:44 a.m. UTC | #2

> Subject: Re: [PATCH v2 18/20] pinctrl: freescale: mxs: Fix refcount of child
> 
> How do you think about to use the summary phrase “Fix reference counting
> for children in mxs_pinctrl_probe_dt()”?

Thanks for reviewing. I have no plan to rework this series for non-accepted
patches. If you have interest and time, feel free to take it.

Thanks,
Peng.
> 
> 
> …
> > of_get_next_child() will increase refcount …
> 
>                                     the reference counter?
> 
> 
> > Per current implementation, 'child' will be override by
> 
>                                               overridden?
> 
> 
> > for_each_child_of_node(np, child), so use of_get_child_count to avoid
> > refcount leakage.
> 
> Another wording suggestion:
>   for_each_child_of_node(np, child). Thus use an of_get_child_count() call
>   to avoid reference counting leakage.
> 
> 
> Regards,
> Markus

Markus Elfring May 30, 2024, 9:50 a.m. UTC | #3

>> How do you think about to use the summary phrase “Fix reference counting
>> for children in mxs_pinctrl_probe_dt()”?
>
> Thanks for reviewing. I have no plan to rework this series for non-accepted patches.
…

Will development interests grow to take patch review concerns better into account
so that commit messages can be improved another bit?

Regards,
Markus

Peng Fan May 30, 2024, 9:54 a.m. UTC | #4

> Subject: Re: [v2 18/20] pinctrl: freescale: mxs: Fix refcount of child
> 
> >> How do you think about to use the summary phrase “Fix reference
> >> counting for children in mxs_pinctrl_probe_dt()”?
> >
> > Thanks for reviewing. I have no plan to rework this series for non-accepted
> patches.
> …
> 
> Will development interests grow to take patch review concerns better into
> account so that commit messages can be improved another bit?

Yes. I had read your comments, since I not plan to redo this series, so not reply
every comment.

Your suggestions are good, I will improve in my future patch commit messages.

Thanks very much!
Peng
> 
> Regards,
> Markus

Patch

diff --git a/drivers/pinctrl/freescale/pinctrl-mxs.c b/drivers/pinctrl/freescale/pinctrl-mxs.c
index aee70fa55bec..edb242d30609 100644
--- a/drivers/pinctrl/freescale/pinctrl-mxs.c
+++ b/drivers/pinctrl/freescale/pinctrl-mxs.c
@@ -413,8 +413,8 @@  static int mxs_pinctrl_probe_dt(struct platform_device *pdev,
 	int ret;
 	u32 val;
 
-	child = of_get_next_child(np, NULL);
-	if (!child) {
+	val = of_get_child_count(np);
+	if (val == 0) {
 		dev_err(&pdev->dev, "no group is defined\n");
 		return -ENOENT;
 	}