From: Johannes Berg <johannes@sipsolutions.net>
Date: Mon, 29 Jul 2019 07:14:22 +0000 (+0200)
Subject: ALSA: aoa: onyx: always initialize register read value
X-Git-Tag: v3.16.79~64
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa9cdfa86181196e566bb1ada4ba8accd591decc;p=thirdparty%2Fkernel%2Fstable.git

ALSA: aoa: onyx: always initialize register read value

commit f474808acb3c4b30552d9c59b181244e0300d218 upstream.

A lot of places in the driver use onyx_read_register() without
checking the return value, and it's been working OK for ~10 years
or so, so probably never fails ... Rather than trying to check the
return value everywhere, which would be relatively intrusive, at
least make sure we don't use an uninitialized value.

Fixes: f3d9478b2ce4 ("[ALSA] snd-aoa: add snd-aoa")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/sound/aoa/codecs/onyx.c b/sound/aoa/codecs/onyx.c
index 401107b85d300..01678e989ebb7 100644
--- a/sound/aoa/codecs/onyx.c
+++ b/sound/aoa/codecs/onyx.c
@@ -74,8 +74,10 @@ static int onyx_read_register(struct onyx *onyx, u8 reg, u8 *value)
 		return 0;
 	}
 	v = i2c_smbus_read_byte_data(onyx->i2c, reg);
-	if (v < 0)
+	if (v < 0) {
+		*value = 0;
 		return -1;
+	}
 	*value = (u8)v;
 	onyx->cache[ONYX_REG_CONTROL-FIRSTREGISTER] = *value;
 	return 0;