diff mbox series

[v4,05/11] driver core: Simplify API device_find_child_by_name() implementation

Message ID 20241211-const_dfc_done-v4-5-583cc60329df@quicinc.com
State Superseded
Headers show
Series driver core: Constify API device_find_child() | expand

Commit Message

Zijun Hu Dec. 11, 2024, 12:08 a.m. UTC 
From: Zijun Hu <quic_zijuhu@quicinc.com>

Simplify device_find_child_by_name() implementation by both existing
API device_find_child() and device_match_name().

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
---
 drivers/base/core.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

Comments

Jonathan Cameron Dec. 23, 2024, 8:39 p.m. UTC | #1 
On Wed, 11 Dec 2024 08:08:07 +0800
Zijun Hu <zijun_hu@icloud.com> wrote:

> From: Zijun Hu <quic_zijuhu@quicinc.com>
> 
> Simplify device_find_child_by_name() implementation by both existing
> API device_find_child() and device_match_name().
There is a subtle difference.  In theory old code could dereference a NULL
if parent->p == NULL, now it can't.  Sounds at most like a harmless change but
maybe you should mention it.

Otherwise LGTM
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> 
> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
> ---
>  drivers/base/core.c | 13 +------------
>  1 file changed, 1 insertion(+), 12 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index bc3b523a4a6366080c3c9fd190e54c7fd13c8ded..8116bc8dd6e9eba0653ca686a90c7008de9e2840 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4110,18 +4110,7 @@ EXPORT_SYMBOL_GPL(device_find_child);
>  struct device *device_find_child_by_name(struct device *parent,
>  					 const char *name)
>  {
> -	struct klist_iter i;
> -	struct device *child;
> -
> -	if (!parent)
> -		return NULL;
> -
> -	klist_iter_init(&parent->p->klist_children, &i);
> -	while ((child = next_device(&i)))
> -		if (sysfs_streq(dev_name(child), name) && get_device(child))
> -			break;
> -	klist_iter_exit(&i);
> -	return child;
> +	return device_find_child(parent, name, device_match_name);
>  }
>  EXPORT_SYMBOL_GPL(device_find_child_by_name);
>  
>
Zijun Hu Dec. 24, 2024, 12:55 p.m. UTC | #2 
On 2024/12/24 04:39, Jonathan Cameron wrote:
> There is a subtle difference.  In theory old code could dereference a NULL
> if parent->p == NULL, now it can't.  Sounds at most like a harmless change but
> maybe you should mention it.
> 

i did not correct parameter checking for device_find_child_by_name() in
below commit

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/base/core.c?id=903c44939abc02e2f3d6f2ad65fa090f7e5df5b6

since this commit will come finally, actually, this commit is the
original motivation of this whole patch series.

> Otherwise LGTM
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
diff mbox series

Patch

diff --git a/drivers/base/core.c b/drivers/base/core.c
index bc3b523a4a6366080c3c9fd190e54c7fd13c8ded..8116bc8dd6e9eba0653ca686a90c7008de9e2840 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4110,18 +4110,7 @@  EXPORT_SYMBOL_GPL(device_find_child);
 struct device *device_find_child_by_name(struct device *parent,
 					 const char *name)
 {
-	struct klist_iter i;
-	struct device *child;
-
-	if (!parent)
-		return NULL;
-
-	klist_iter_init(&parent->p->klist_children, &i);
-	while ((child = next_device(&i)))
-		if (sysfs_streq(dev_name(child), name) && get_device(child))
-			break;
-	klist_iter_exit(&i);
-	return child;
+	return device_find_child(parent, name, device_match_name);
 }
 EXPORT_SYMBOL_GPL(device_find_child_by_name);