| Message ID | 20200628155231.71089-5-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 3f31f7d9b5404a10648abe536c8b408bfb4502e1 |
| Headers | show |
| Series | [1/6] ASoC: Intel: cht_bsw_rt5672: Change bus format to I2S 2 channel | expand |
On 6/28/20 10:52 AM, Hans de Goede wrote: > The adc_vol_tlv volume-control has a range from -17.625 dB to +30 dB, > not -176.25 dB to + 300 dB. This wrong scale is esp. a problem in userspace D'oh! nice catch. > apps which translate the dB scale to a linear scale. With the logarithmic > dB scale being of by a factor of 10 we loose all precision in the lower > area of the range when apps translate things to a linear scale. > > E.g. the 0 dB default, which corresponds with a value of 47 of the > 0 - 127 range for the control, would be shown as 0/100 in alsa-mixer. > > Since the centi-dB values used in the TLV struct cannot represent the > 0.375 dB step size used by these controls, change the TLV definition > for them to specify a min and max value instead of min + stepsize. > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > sound/soc/codecs/rt5670.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/sound/soc/codecs/rt5670.c b/sound/soc/codecs/rt5670.c > index f21181734170..dfbc0ca38ff7 100644 > --- a/sound/soc/codecs/rt5670.c > +++ b/sound/soc/codecs/rt5670.c > @@ -603,9 +603,9 @@ int rt5670_set_jack_detect(struct snd_soc_component *component, > EXPORT_SYMBOL_GPL(rt5670_set_jack_detect); > > static const DECLARE_TLV_DB_SCALE(out_vol_tlv, -4650, 150, 0); > -static const DECLARE_TLV_DB_SCALE(dac_vol_tlv, -65625, 375, 0); > +static const DECLARE_TLV_DB_MINMAX(dac_vol_tlv, -6562, 0); > static const DECLARE_TLV_DB_SCALE(in_vol_tlv, -3450, 150, 0); > -static const DECLARE_TLV_DB_SCALE(adc_vol_tlv, -17625, 375, 0); > +static const DECLARE_TLV_DB_MINMAX(adc_vol_tlv, -1762, 3000); > static const DECLARE_TLV_DB_SCALE(adc_bst_tlv, 0, 1200, 0); > > /* {0, +20, +24, +30, +35, +40, +44, +50, +52} dB */ >
diff --git a/sound/soc/codecs/rt5670.c b/sound/soc/codecs/rt5670.c index f21181734170..dfbc0ca38ff7 100644 --- a/sound/soc/codecs/rt5670.c +++ b/sound/soc/codecs/rt5670.c @@ -603,9 +603,9 @@ int rt5670_set_jack_detect(struct snd_soc_component *component, EXPORT_SYMBOL_GPL(rt5670_set_jack_detect); static const DECLARE_TLV_DB_SCALE(out_vol_tlv, -4650, 150, 0); -static const DECLARE_TLV_DB_SCALE(dac_vol_tlv, -65625, 375, 0); +static const DECLARE_TLV_DB_MINMAX(dac_vol_tlv, -6562, 0); static const DECLARE_TLV_DB_SCALE(in_vol_tlv, -3450, 150, 0); -static const DECLARE_TLV_DB_SCALE(adc_vol_tlv, -17625, 375, 0); +static const DECLARE_TLV_DB_MINMAX(adc_vol_tlv, -1762, 3000); static const DECLARE_TLV_DB_SCALE(adc_bst_tlv, 0, 1200, 0); /* {0, +20, +24, +30, +35, +40, +44, +50, +52} dB */
The adc_vol_tlv volume-control has a range from -17.625 dB to +30 dB, not -176.25 dB to + 300 dB. This wrong scale is esp. a problem in userspace apps which translate the dB scale to a linear scale. With the logarithmic dB scale being of by a factor of 10 we loose all precision in the lower area of the range when apps translate things to a linear scale. E.g. the 0 dB default, which corresponds with a value of 47 of the 0 - 127 range for the control, would be shown as 0/100 in alsa-mixer. Since the centi-dB values used in the TLV struct cannot represent the 0.375 dB step size used by these controls, change the TLV definition for them to specify a min and max value instead of min + stepsize. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- sound/soc/codecs/rt5670.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)