media: em28xx: calculate left volume level correctly
authorColin Ian King <colin.king@canonical.com>
Tue, 22 Aug 2017 14:21:20 +0000 (10:21 -0400)
committerBen Hutchings <ben@decadent.org.uk>
Sun, 26 Nov 2017 13:51:04 +0000 (13:51 +0000)
commit 801e3659bf2c87c31b7024087d61e89e172b5651 upstream.

The calculation of the left volume looks suspect, the value of
0x1f - ((val << 8) & 0x1f) is always 0x1f. The debug prior to the
assignment of value[1] prints the left volume setting using the
calculation 0x1f - (val >> 8) & 0x1f which looks correct to me.
Fix the left volume by using the correct expression as used in
the debug.

Detected by CoverityScan, CID#146140 ("Wrong operator used")

Fixes: 850d24a5a861 ("[media] em28xx-alsa: add mixer support for AC97 volume controls")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
drivers/media/video/em28xx/em28xx-audio.c

index cff0768..e902bf5 100644 (file)
@@ -507,7 +507,7 @@ static int em28xx_vol_get(struct snd_kcontrol *kcontrol,
                val, (int)kcontrol->private_value);
 
        value->value.integer.value[0] = 0x1f - (val & 0x1f);
-       value->value.integer.value[1] = 0x1f - ((val << 8) & 0x1f);
+       value->value.integer.value[1] = 0x1f - ((val >> 8) & 0x1f);
 
        return 0;
 }