Re: [PATCH 2/4] ASoC: rt5670: Remove 'HP Playback Switch' control

[Jaroslav Kysela <perex@perex.cz>]

Dne 16. 02. 21 v 16:15 Hans de Goede napsal(a):
> Hi,
> 
> On 2/15/21 7:09 PM, Jaroslav Kysela wrote:
>> Dne 15. 02. 21 v 15:21 Hans de Goede napsal(a):
>>> The RT5670_L_MUTE_SFT and RT5670_R_MUTE_SFT bits (bits 15 and 7) of the
>>> RT5670_HP_VOL register are set / unset by the headphones deplop code
>>> run by rt5670_hp_event() on SND_SOC_DAPM_POST_PMU / SND_SOC_DAPM_PRE_PMD.
>>>
>>> So we should not also export a control to userspace which toggles these
>>> same bits.
>>
>> I think that it may be worth to preserve the full-mute functionality.
>> According the datasheet, the register 0x02 has volume range -46.5dB..12dB.
>> Even the lowest volume may produce an audible output.
>>
>> I would cache the mute switch value in rt5670_priv and update the
>> POST_PMU/PRE_PMD code to use this settings.
> 
> Yes that should work.
> 
> Note though that patch 4/4 adds a mute for the master volume control, even
> though I call it an "emulated" mute it is a full mute, it is just that
> we now have 2 switches, 1 mixer switch and 1 mute switch, which must
> both be true before we enable the path from the DAC through the mixer
> which sits directly behind the "DAC1 Playback Volume" control.
> 
> And we need that mute anyways because the speaker output does not
> have any volume control other then the master "DAC1 Playback Volume"
> which has the same issue of only going very soft and not going to
> a full mute.
> 
> So since we have a working mute in the master volume control, we don't
> really need one for the "HP Playback Volume" control. with that all said,
> your suggestion should work fine.
> 
> So the question is do we want to do as you suggest, or are we happy
> with just having the master mute ?

One hw mute per one hw output should be sufficient. Thank you for the explanation.

					Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.