V4L/DVB: cx88-alsa: prevent out-of-range volume setting

Ensure that volume values are always in the allowed range.  Otherwise,
it would be possible to set other bits in the AUD_VOL_CTL register or to
get a wrong sign in the AUD_BAL_CTL register.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Clemens Ladisch 2010-02-22 06:45:07 -03:00 committed by Mauro Carvalho Chehab
parent 071193ff41
commit cca80b9732

View File

@ -583,16 +583,18 @@ static int snd_cx88_volume_put(struct snd_kcontrol *kcontrol,
{
snd_cx88_card_t *chip = snd_kcontrol_chip(kcontrol);
struct cx88_core *core=chip->core;
int v, b;
int left, right, v, b;
int changed = 0;
u32 old;
b = value->value.integer.value[1] - value->value.integer.value[0];
left = value->value.integer.value[0] & 0x3f;
right = value->value.integer.value[1] & 0x3f;
b = right - left;
if (b < 0) {
v = 0x3f - value->value.integer.value[0];
v = 0x3f - left;
b = (-b) | 0x40;
} else {
v = 0x3f - value->value.integer.value[1];
v = 0x3f - right;
}
/* Do we really know this will always be called with IRQs on? */
spin_lock_irq(&chip->reg_lock);