linux-kernel - [PATCH AUTOSEL 4.9 06/19] ALSA: sb8: Add a comment note regarding an unused pointer

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Message-Id: <20210524145106.2499571-6-sashal@kernel.org>
Date:   Mon, 24 May 2021 10:50:53 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Atul Gopinathan <atulgopinathan@...il.com>,
        Takashi Iwai <tiwai@...e.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Sasha Levin <sashal@...nel.org>, alsa-devel@...a-project.org
Subject: [PATCH AUTOSEL 4.9 06/19] ALSA: sb8: Add a comment note regarding an unused pointer

From: Atul Gopinathan <atulgopinathan@...il.com>

[ 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>
---
 sound/isa/sb/sb8.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/sound/isa/sb/sb8.c b/sound/isa/sb/sb8.c
index e75bfc511e3e..f7a7995588f2 100644
--- a/sound/isa/sb/sb8.c
+++ 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 (!acard->fm_res) {
 		err = -EBUSY;
-- 
2.30.2