linux-kernel - Re: sound/pci/ctxfi/ctdaio.c: duplicate function removal question

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Message-ID: <20241229090228.75f8a3ba@dsl-u17-10>
Date: Sun, 29 Dec 2024 09:02:28 +0000
From: David Laight <david.laight.linux@...il.com>
To: Ethan Carter Edwards <ethan@...ancedwards.com>
Cc: "wychay@....creative.com" <wychay@....creative.com>,
 "ryan_richards@...ativelabs.com" <ryan_richards@...ativelabs.com>,
 "tiwai@...e.de" <tiwai@...e.de>, "linux-sound@...r.kernel.org"
 <linux-sound@...r.kernel.org>, "linux-kernel@...r.kernel.org"
 <linux-kernel@...r.kernel.org>
Subject: Re: sound/pci/ctxfi/ctdaio.c: duplicate function removal question

On Tue, 24 Dec 2024 23:16:17 +0000
Ethan Carter Edwards <ethan@...ancedwards.com> wrote:

> Hello all,
> 
> First of all, happy holidays. 
> 
> I was browsing the ctdaio.c code and I noticed a lot of 
> duplicate code and functions, specifically:
> 
> dao_set_{right,left}_input and
> dao_clear_{right,left}_input functions.
> 
> The functions are pretty much identical. They only 
> differ in the side (left, right). What was the original
> idea in doing this? Wouldn't it make more since to just
> have an ENUM (left, right) as an argument that would 
> determine the side and just reduce the function to 
> dao_set_input and dao_clear_input.

Hmmm... you'd have a lot of conditionals inside the function.

They also look like a memory leak just waiting to happen.
I guess that an earlier implementation used a separate kmalloc()
for each imappers[].

Why is imappers[] an array of pointers not an array of the items?
Each is just 8 bytes plus a 'list_head' (2 pointers?).

	David

> 
> I would be more than happy to send in a patch doing
> these changes, but before I did I wanted to ask if
> there was a reason the code was written in this way.
> I am pretty new to kernel development.
> 
> Thanks,
> Ethan
> --
> Ethan Carter Edwards
> CompTIA A+, Security+, and ISC2 (CC)
> Ham Radio: AE4CE
> Website: https://ethancedwards.com
> 
>