linux-kernel - Re: [PATCH v7 2/2] staging: rtl8723bs: Use % 4096 instead of & 0xfff

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Message-ID: <CADYq+fZFRF5SLLyfG12hUJLjNk+njWyC6H34S_warp61zYv8wQ@mail.gmail.com>
Date: Tue, 8 Apr 2025 16:44:24 +0100
From: Samuel Abraham <abrahamadekunle50@...il.com>
To: Andy Shevchenko <andy@...nel.org>
Cc: outreachy@...ts.linux.dev, julia.lawall@...ia.fr, 
	gregkh@...uxfoundation.org, linux-staging@...ts.linux.dev, 
	linux-kernel@...r.kernel.org, david.laight.linux@...il.com, 
	dan.carpenter@...aro.org
Subject: Re: [PATCH v7 2/2] staging: rtl8723bs: Use % 4096 instead of & 0xfff

On Tue, Apr 8, 2025 at 4:12 PM Andy Shevchenko <andy@...nel.org> wrote:
>
> On Tue, Apr 08, 2025 at 01:31:42PM +0000, Abraham Samuel Adekunle wrote:
> > The sequence number is constrained to a range of [0, 4095], which
> > is a total of 4096 values. The bitmask operation using `& 0xfff` is
> > used to perform this wrap-around. While this is functionally correct,
> > it obscures the intended semantic of a 4096-based wrap.
> >
> > Using a modulo operation `% 4096u` makes the wrap-around logic
> > explicit and easier to understand. It clearly signals that the
> > sequence number cycles through a range of 4096 values.
> > It also makes the code robust against potential changes of the 4096
> > upper limit, especially when it becomes a non power of 2 value while
>
> power-of-2
>
> > the AND(&) works solely for power of 2 values.
>
> power-of-2
>
> > The use of `% 4096u` also guarantees that the modulo operation is
> > performed with unsigned arithmetic, preventing potential issues with
> > the signed types.
>
> Reviewed-by: Andy Shevchenko <andy@...nel.org>

Thank you, Andy for your patience with me and guidance and the review.

I have sent the updated patch.

Adekunle.