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

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Message-ID: <144a8a27-ac7a-6d3b-1744-26fe0806deee@perex.cz>
Date:   Thu, 5 Jan 2023 13:43:15 +0100
From:   Jaroslav Kysela <perex@...ex.cz>
To:     Kai-Heng Feng <kai.heng.feng@...onical.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
Cc:     tiwai@...e.com, Bard Liao <yung-chuan.liao@...ux.intel.com>,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ALSA: hda: Skip creating captures in SOF context

On 05. 01. 23 13:36, Kai-Heng Feng wrote:
> On Mon, Aug 15, 2022 at 3:55 PM Kai-Heng Feng
> <kai.heng.feng@...onical.com> wrote:
>>
>> On Wed, Jul 20, 2022 at 9:31 PM Pierre-Louis Bossart
>> <pierre-louis.bossart@...ux.intel.com> wrote:
>>>
>>>
>>>
>>> On 7/20/22 02:52, Jaroslav Kysela wrote:
>>>> 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 ?
>>>
>>> The HDA codec is connected in the same way in all cases, there's no
>>> hardware/electrical/routing difference.
>>>
>>> When used, the SOF driver will handle ALL links, be they DMIC or
>>> HDAudio. The difference for HDaudio is that instead of a single DMA
>>> transfer (DDR->FIFO), we have a first 'Host' DMA into the DSP SRAM, some
>>> processing and a second 'Link' DMA from DSP SRAM to the HDaudio FIFO
>>> (reversed flow for capture).
>>
>> So is this approach sufficient for this issue? Or should I explore
>> other possibilities?
> 
> A gentle ping...

This Mic LED problem was resolved through UCM for the moment:

https://github.com/alsa-project/alsa-ucm-conf/commit/79a8ec44d3dcf097f4a4492c506cbcf338324175

More discussion:

https://bugzilla.redhat.com/show_bug.cgi?id=2134824

					Jaroslav

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