[PATCH 4.19 080/116] ALSA: sb8: Add a comment note regarding an unused pointer

From: Greg Kroah-Hartman
Date: Mon May 31 2021 - 09:47:18 EST


From: Atul Gopinathan <atulgopinathan@xxxxxxxxx>

[ 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@xxxxxxx>
Signed-off-by: Atul Gopinathan <atulgopinathan@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210503115736.2104747-36-gregkh@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 d77dcba276b5..b0ef47bc6521 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 (port[dev] != SNDRV_AUTO_PORT) {
--
2.30.2