linux-kernel - Re: [PATCH] ALSA: hda: Skip creating captures in SOF context

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Message-ID: <34bddb2f-dc57-c08c-358e-26cf7824c203@perex.cz>
Date:   Wed, 20 Jul 2022 09:52:37 +0200
From:   Jaroslav Kysela <perex@...ex.cz>
To:     Kai-Heng Feng <kai.heng.feng@...onical.com>
Cc:     tiwai@...e.com, Bard Liao <yung-chuan.liao@...ux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ALSA: hda: Skip creating captures in SOF context

Dne 20. 07. 22 v 3:45 Kai-Heng Feng napsal(a):
> On Tue, Jul 19, 2022 at 11:41 PM Jaroslav Kysela <perex@...ex.cz> wrote:
>>
>> Dne 19. 07. 22 v 16:47 Kai-Heng Feng napsal(a):
>>> On HP laptops that use SOF driver for DMIC, the micmute LED doesn't
>>> light up when mic is muted after commit 9b014266ef8a ("ASoC: SOF:
>>> topology: use new sound control LED layer").
>>>
>>> The micmute LED itself is still working via sysfs, but it doesn't follow
>>> mute anymore. That's because unlike vendors like Dell and Lenovo, HP
>>> laptops use HDA codec to control mute LEDs instead of ACPI. So on HP
>>> laptops, both SOF and HDA create captures with
>>> SNDRV_CTL_ELEM_ACCESS_MIC_LED access, snd_ctl_led_set_state() considers
>>> there are two different kcontrols and one of them is not muted.
>>
>> It does not mean that it's a wrong behavior. When both controls are muted, the
>> LED should be turned on. It just requires that all inputs are off (and it may
>> be the default - probably we can set in UCM or so). If you turn the "Capture
>> Switch" off in amixer / alsamixer, do things work as expected ?
> 
> Yes. When all captures are muted the micmute LED is on.
> 
>>
>>> So skip creating captures for HDA when it's called from SOF, the
>>> captures are already handled by SOF.
>>
>> The capture controls are for other inputs like external analog microphone. If
>> it is required to suppress the MIC LED for some hardware, just skip the
>> "spec->mic_mute_led = 1" assignment in hda_generic.c . Also, the check
>> "codec->core.type != HDA_DEV_ASOC" is not sufficient, because you don't know,
>> if the topology really sets the MIC LED flag.
> 
> AFAIK the external analog microphone on DMIC laptop is driven by SOF driver too.
> If those capture controls are indeed needed for external analog mics,
> use UCM to mute them by default won't work either.

Could you describe this ? I though that only DMIC is handled by SOF when HDA
codec is in the system. There is a separate analog codec for external analog
microphone or the HDA codec is somehow connected to SOF/DSP ? If so, how ?

					Jaroslav

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