linux-kernel - Re: [PATCH 4.4 35/54] ALSA: sb8: Add a comment note regarding an unused pointer

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Message-ID: <20210531203638.GA19276@amd>
Date:   Mon, 31 May 2021 22:36:38 +0200
From:   Pavel Machek <pavel@...x.de>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        Takashi Iwai <tiwai@...e.de>,
        Atul Gopinathan <atulgopinathan@...il.com>,
        Sasha Levin <sashal@...nel.org>
Subject: Re: [PATCH 4.4 35/54] ALSA: sb8: Add a comment note regarding an
 unused pointer

Hi!

> [ Upstream commit a28591f61b60fac820c6de59826ffa710e5e314e ]
> 
> The field "fm_res" of "struct snd_sb8" is never used/dereferenced
> throughout the sb8.c code. Therefore there is no need for any null value
> check after the "request_region()".
> 
> Add a comment note to make developers know about this and prevent any
> "NULL check" patches on this part of code.
> 
> Cc: Takashi Iwai <tiwai@...e.de>
> Signed-off-by: Atul Gopinathan <atulgopinathan@...il.com>
> Link: https://lore.kernel.org/r/20210503115736.2104747-36-gregkh@linuxfoundation.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
> Signed-off-by: Sasha Levin <sashal@...nel.org>

This simply adds a comment... As I'm pretty sure anyone trying to
"fix" this will try that on mainline, it is even very useful comment.

That's something our documentation says we don't do in stable. I'd
prefer it not to be in.

Best regards,
								Pavel

> +++ b/sound/isa/sb/sb8.c
> @@ -109,7 +109,11 @@ static int snd_sb8_probe(struct device *pdev, unsigned int dev)
>  	acard = card->private_data;
>  	card->private_free = snd_sb8_free;
>  
> -	/* block the 0x388 port to avoid PnP conflicts */
> +	/*
> +	 * Block the 0x388 port to avoid PnP conflicts.
> +	 * No need to check this value after request_region,
> +	 * as we never do anything with it.
> +	 */
>  	acard->fm_res = request_region(0x388, 4, "SoundBlaster FM");
>  
>  	if (port[dev] != SNDRV_AUTO_PORT) {

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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