linux-kernel - Re: [PATCH v3 1/2] ALSA: hda: cs35l41: Support mute notifications for CS35L41 HDA

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Date:   Wed, 20 Sep 2023 08:58:16 +0200
From:   Takashi Iwai <tiwai@...e.de>
To:     Stefan Binding <sbinding@...nsource.cirrus.com>
Cc:     Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>,
        <alsa-devel@...a-project.org>, <linux-kernel@...r.kernel.org>,
        <patches@...nsource.cirrus.com>,
        Vitaly Rodionov <vitalyr@...nsource.cirrus.com>
Subject: Re: [PATCH v3 1/2] ALSA: hda: cs35l41: Support mute notifications for CS35L41 HDA

On Tue, 19 Sep 2023 16:22:39 +0200,
Stefan Binding wrote:
> 
> From: Vitaly Rodionov <vitalyr@...nsource.cirrus.com>
> 
> Some laptops require a hardware based mute system, where when a hotkey
> is pressed, it forces the amp to be muted.
> 
> For CS35L41, when the hotkey is pressed, an acpi notification is sent
> to the CS35L41 Device Node. The driver needs to handle this notification
> and call a _DSM function to retrieve the mute state.
> 
> Since the amp is only muted during playback, the driver will only mute
> or unmute if playback is occurring, otherwise it will save the mute
> state for when playback starts.
> 
> Only one handler can be registered for the acpi notification, but all
> amps need to receive that notification, we can register a single handler
> inside the Realtek HDA driver, so that it can then notify through the
> component framework.
> 
> Signed-off-by: Vitaly Rodionov <vitalyr@...nsource.cirrus.com>
> Signed-off-by: Stefan Binding <sbinding@...nsource.cirrus.com>

The patch is a bit lengthy.  I'd split the binding of patch_realtek.c
into another patch.  That part is fairly generic.

> --- a/sound/pci/hda/patch_realtek.c
> +++ b/sound/pci/hda/patch_realtek.c
(snip)
> +static void comp_acpi_device_notify(acpi_handle handle, u32 event, void *data)
> +{
> +	struct hda_codec *cdc = data;
> +	struct alc_spec *spec = cdc->spec;
> +	int i;
> +
> +	codec_info(cdc, "ACPI Notification %d\n", event);
> +
> +	for (i = 0; i < HDA_MAX_COMPONENTS; i++) {
> +		if (spec->comps[i].dev && spec->comps[i].acpi_notify)
> +			spec->comps[i].acpi_notify(acpi_device_handle(spec->comps[i].adev), event,
> +						   spec->comps[i].dev);
> +	}
> +}

This function should be in #ifdef CONFIG_ACPI, too.


thanks,

Takashi