[PATCH 6.8 546/715] ALSA: scarlett2: Fix Scarlett 4th Gen input gain range

Sasha Levin
2024-03-24T22:43:59Z

From: "Geoffrey D. Bennett" <g@b4.vu>

[ Upstream commit a45cf0a0834779c741ac204c0320469e9aaef006 ]

The input gain range TLV was declared as -70dB to 0dB, but the preamp
gain range is actually 0dB to +70dB. Rename SCARLETT2_GAIN_BIAS to
SCARLETT2_MAX_GAIN and update the TLV to fix.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Fixes: 0a995e38dc44 ("ALSA: scarlett2: Add support for software-controllable input gain")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Message-ID: <9168317b5ac5335943d3f14dbcd1cc2d9b2299d0.1710047969.git.g@b4.vu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/usb/mixer_scarlett2.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sound/usb/mixer_scarlett2.c b/sound/usb/mixer_scarlett2.c
index 3815ce1d216e6..ffb8bcebf9ad6 100644
--- a/sound/usb/mixer_scarlett2.c
+++ b/sound/usb/mixer_scarlett2.c
@@ -173,7 +173,9 @@

/* some gui mixers can't handle negative ctl values */
#define SCARLETT2_VOLUME_BIAS 127
-#define SCARLETT2_GAIN_BIAS 70
+
+/* maximum preamp input gain */
+#define SCARLETT2_MAX_GAIN 70

/* mixer range from -80dB to +6dB in 0.5dB steps */
#define SCARLETT2_MIXER_MIN_DB -80
@@ -3464,7 +3466,7 @@ static int scarlett2_input_gain_ctl_info(struct snd_kcontrol *kctl,
uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
uinfo->count = elem->channels;
uinfo->value.integer.min = 0;
- uinfo->value.integer.max = SCARLETT2_GAIN_BIAS;
+ uinfo->value.integer.max = SCARLETT2_MAX_GAIN;
uinfo->value.integer.step = 1;

unlock:
@@ -3541,7 +3543,7 @@ static int scarlett2_input_gain_ctl_put(struct snd_kcontrol *kctl,
}

static const DECLARE_TLV_DB_MINMAX(
- db_scale_scarlett2_gain, -SCARLETT2_GAIN_BIAS * 100, 0
+ db_scale_scarlett2_gain, 0, SCARLETT2_MAX_GAIN * 100
);

static const struct snd_kcontrol_new scarlett2_input_gain_ctl = {
--
2.43.0