diff mbox series

[1/7] drivers/rtc/sysfs: move code to count_attribute_groups()

Message ID 20231009165741.746184-1-max.kellermann@ionos.com
State New
Headers
Series [1/7] drivers/rtc/sysfs: move code to count_attribute_groups() |

Commit Message

Max Kellermann Oct. 9, 2023, 4:57 p.m. UTC 
  This avoids overloading the "groups" variable for three different
purposes

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
---
 drivers/rtc/sysfs.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

Comments

Greg KH Oct. 9, 2023, 5:24 p.m. UTC | #1 
On Mon, Oct 09, 2023 at 06:57:34PM +0200, Max Kellermann wrote:
> This avoids overloading the "groups" variable for three different
> purposes

What 3 different purposes?

And you sent a patch series that hit a lot of different subsystems and
maintainers all at once, but you didn't cc: all of us.  Who is supposed
to take these?

But step back, _WHY_ are all of these changes needed?  I don't see a
cover letter explaining the rational, and on their own, they really
don't do anything, so it's really confusing as to what is going on here.

thanks,

greg k-h
Max Kellermann Oct. 9, 2023, 6:01 p.m. UTC | #2 
On Mon, Oct 9, 2023 at 7:24 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> What 3 different purposes?

The variable gets initialized 3 times with different (unrelated) values:

1. count old rtc->dev.groups
2. count grps
3. allocate new rtc->dev.groups

This coding style is confusing and error prone. The code gets simpler
with this patch, because the cognitive load of understanding a
"count_attribute_groups()" call is lower than reading the "while" loop
and figuring out why it's there.

But I really wrote this patch because after making "rtc->dev.groups"
const, I cannot any longer assign it to "groups", because that
variable must remain non-const.
Alexandre Belloni Oct. 10, 2023, 8:15 a.m. UTC | #3 
On 09/10/2023 18:57:34+0200, Max Kellermann wrote:
> This avoids overloading the "groups" variable for three different
> purposes
> 
> Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
> ---
>  drivers/rtc/sysfs.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/rtc/sysfs.c b/drivers/rtc/sysfs.c
> index e3062c4d3f2c..617933d52324 100644
> --- a/drivers/rtc/sysfs.c
> +++ b/drivers/rtc/sysfs.c
> @@ -313,21 +313,25 @@ const struct attribute_group **rtc_get_dev_attribute_groups(void)
>  	return rtc_attr_groups;
>  }
>  
> +static size_t count_attribute_groups(const struct attribute_group *const*groups)

Shouldn't that live out of the rtc subsystem?

> +{
> +	size_t count = 0;
> +
> +	for (; *groups; ++groups)
> +		++count;
> +	return count;
> +}
> +
>  int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
>  {
> -	size_t old_cnt = 0, add_cnt = 0, new_cnt;
> +	size_t old_cnt, add_cnt, new_cnt;
>  	const struct attribute_group **groups, **old;
>  
>  	if (!grps)
>  		return -EINVAL;
>  
> -	groups = rtc->dev.groups;
> -	if (groups)
> -		for (; *groups; groups++)
> -			old_cnt++;
> -
> -	for (groups = grps; *groups; groups++)
> -		add_cnt++;
> +	old_cnt = rtc->dev.groups ? count_attribute_groups(rtc->dev.groups) : 0;
> +	add_cnt = count_attribute_groups(grps);
>  
>  	new_cnt = old_cnt + add_cnt + 1;
>  	groups = devm_kcalloc(&rtc->dev, new_cnt, sizeof(*groups), GFP_KERNEL);
> -- 
> 2.39.2
>
Max Kellermann Oct. 10, 2023, 8:24 a.m. UTC | #4 
On Tue, Oct 10, 2023 at 10:15 AM Alexandre Belloni
<alexandre.belloni@bootlin.com> wrote:
> Shouldn't that live out of the rtc subsystem?

You suggest making this a global function? Sure, if that's preferred,
I'll change it. Whose decision is this?
diff mbox series

Patch

diff --git a/drivers/rtc/sysfs.c b/drivers/rtc/sysfs.c
index e3062c4d3f2c..617933d52324 100644
--- a/drivers/rtc/sysfs.c
+++ b/drivers/rtc/sysfs.c
@@ -313,21 +313,25 @@  const struct attribute_group **rtc_get_dev_attribute_groups(void)
 	return rtc_attr_groups;
 }
 
+static size_t count_attribute_groups(const struct attribute_group *const*groups)
+{
+	size_t count = 0;
+
+	for (; *groups; ++groups)
+		++count;
+	return count;
+}
+
 int rtc_add_groups(struct rtc_device *rtc, const struct attribute_group **grps)
 {
-	size_t old_cnt = 0, add_cnt = 0, new_cnt;
+	size_t old_cnt, add_cnt, new_cnt;
 	const struct attribute_group **groups, **old;
 
 	if (!grps)
 		return -EINVAL;
 
-	groups = rtc->dev.groups;
-	if (groups)
-		for (; *groups; groups++)
-			old_cnt++;
-
-	for (groups = grps; *groups; groups++)
-		add_cnt++;
+	old_cnt = rtc->dev.groups ? count_attribute_groups(rtc->dev.groups) : 0;
+	add_cnt = count_attribute_groups(grps);
 
 	new_cnt = old_cnt + add_cnt + 1;
 	groups = devm_kcalloc(&rtc->dev, new_cnt, sizeof(*groups), GFP_KERNEL);