From: Clemens Ladisch <clemens@ladisch.de>
Date: Tue, 26 Aug 2008 09:06:26 +0000 (+0200)
Subject: ALSA: oxygen: prevent muting of nonexistent AC97 controls
X-Git-Tag: v2.6.27-rc5~24^2~1
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3d839e5b87a70effc629c1cdbf77d837ef141919;p=linux-2.6

ALSA: oxygen: prevent muting of nonexistent AC97 controls

The Xonar DX does not have CD Capture controls, so we have to check that
a control actually exists before muting it.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/pci/oxygen/oxygen_mixer.c b/sound/pci/oxygen/oxygen_mixer.c
index 6facac5aed..05eb8994c1 100644
--- a/sound/pci/oxygen/oxygen_mixer.c
+++ b/sound/pci/oxygen/oxygen_mixer.c
@@ -512,9 +512,12 @@ static int ac97_switch_get(struct snd_kcontrol *ctl,
 
 static void mute_ac97_ctl(struct oxygen *chip, unsigned int control)
 {
-	unsigned int priv_idx = chip->controls[control]->private_value & 0xff;
+	unsigned int priv_idx;
 	u16 value;
 
+	if (!chip->controls[control])
+		return;
+	priv_idx = chip->controls[control]->private_value & 0xff;
 	value = oxygen_read_ac97(chip, 0, priv_idx);
 	if (!(value & 0x8000)) {
 		oxygen_write_ac97(chip, 0, priv_idx, value | 0x8000);