[alsa-devel] [PATCH - ice1724 1/1] ALSA: ice1724 - Check for ac97 to avoid kernel oops

[pavel.hofman at ivitera.com]

From: Pavel Hofman <pavel.hofman at ivitera.com>

Cards with identical PCI ids but no AC97 config in EEPROM do not have
the ac97 field initialized. We must check for this case to avoid kernel oops.

Signed-off-by: Pavel Hofman <pavel.hofman at ivitera.com>

diff --git a/pci/ice1712/amp.c b/pci/ice1712/amp.c
index e328cfb..e525da2 100644
--- a/pci/ice1712/amp.c
+++ b/pci/ice1712/amp.c
@@ -68,8 +68,11 @@ static int __devinit snd_vt1724_amp_init(struct snd_ice1712 *ice)
 
 static int __devinit snd_vt1724_amp_add_controls(struct snd_ice1712 *ice)
 {
-	/* we use pins 39 and 41 of the VT1616 for left and right read outputs */
-	snd_ac97_write_cache(ice->ac97, 0x5a, snd_ac97_read(ice->ac97, 0x5a) & ~0x8000);
+	if (ice->ac97)
+		/* we use pins 39 and 41 of the VT1616 for left and right
+		read outputs */
+		snd_ac97_write_cache(ice->ac97, 0x5a,
+			snd_ac97_read(ice->ac97, 0x5a) & ~0x8000);
 	return 0;
 }
 
-- 
1.7.0.4