ALSA: 6fire: Fix input volume change detection

usb6fire_control_input_vol_put() stores the analog capture volume
as a signed offset in rt->input_vol[] (-15..+15), but it compares
the cached value against the user-visible mixer value (0..30)
before subtracting 15.

This mixes two domains in the change detection path. Since the
runtime is zero-initialized, the visible default is 15; writing 0
right after probe is ignored, while writing 15 is reported as a
change even though the cached value remains 0.

Normalize the user value before comparing it with the cached offset.

Fixes: 06bb4e743501 ("ALSA: snd-usb-6fire: add analog input volume control")
Cc: stable@vger.kernel.org
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260416-alsa-6fire-input-volume-change-detection-v1-1-ec78299168df@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/6fire/control.c b/sound/usb/6fire/control.c
index dd25a6407b6385abe88aa731187731229aba3576..c77a21a9acd796d09bafbb22e16f013da54178d2 100644 (file)
--- a/sound/usb/6fire/control.c
+++ b/sound/usb/6fire/control.c
@@ -290,15 +290,17 @@ static int usb6fire_control_input_vol_put(struct snd_kcontrol *kcontrol,
                struct snd_ctl_elem_value *ucontrol)
 {
        struct control_runtime *rt = snd_kcontrol_chip(kcontrol);
+       int vol0 = ucontrol->value.integer.value[0] - 15;
+       int vol1 = ucontrol->value.integer.value[1] - 15;
        int changed = 0;
 
-       if (rt->input_vol[0] != ucontrol->value.integer.value[0]) {
-               rt->input_vol[0] = ucontrol->value.integer.value[0] - 15;
+       if (rt->input_vol[0] != vol0) {
+               rt->input_vol[0] = vol0;
                rt->ivol_updated &= ~(1 << 0);
                changed = 1;
        }
-       if (rt->input_vol[1] != ucontrol->value.integer.value[1]) {
-               rt->input_vol[1] = ucontrol->value.integer.value[1] - 15;
+       if (rt->input_vol[1] != vol1) {
+               rt->input_vol[1] = vol1;
                rt->ivol_updated &= ~(1 << 1);
                changed = 1;
        }