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References: <20231009165741.746184-1-max.kellermann@ionos.com> <2023100943-anew-choking-5954@gregkh>
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From:   Max Kellermann <max.kellermann@ionos.com>
Date:   Mon, 9 Oct 2023 20:01:43 +0200
Message-ID: <CAKPOu+_CEJH0zfk5PQU5dxFY8ZiYjFvvAG2GXPM_3Fr2_om8Xw@mail.gmail.com>
Subject: Re: [PATCH 1/7] drivers/rtc/sysfs: move code to count_attribute_groups()
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     Alessandro Zummo <a.zummo@towertech.it>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org
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On Mon, Oct 9, 2023 at 7:24=E2=80=AFPM 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.