Asus Zephyrus G16 2025 GU605CR: sound issue

[atimofeev]

Basically, only tweeters are operational, while mid and low frequency speakers are silent.

From what I see, the main culprit here is Cirrus cs35l56 amp and it's configuration.

Judging from dmesg, device is initialized:

[root@zefir:/home/atimofeev]# dmesg | grep cs35l56
[    3.988046] cs35l56-hda spi0-CSC3556:00-cs35l56-hda.0: Cirrus Logic CS35L56 Rev B0 OTP3 fw:3.4.4 (patched=0)
[    4.010950] cs35l56-hda spi0-CSC3556:00-cs35l56-hda.0: DSP system name: '10431034-spkid0', amp name: 'AMP1'
[    4.072434] snd_hda_codec_alc269 hdaudioC0D0: Found 2 CSC3556 on spi (-%s:00-cs35l56-hda.%d)

I've tried many kernel options with sof-firmware modules, but I can't get anywhere with this.

Kernel: 6.17
OS: NixOS 25.05

[atimofeev]

Found this issue in linux kernel bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=220152
Will try to adapt the patches in nix configuration

[atimofeev]

Kernel patch for proper volume control is already implemented in 6.16, as I see from source code:

	SND_PCI_QUIRK(0x1043, 0x1034, "ASUS GU605C", ALC285_FIXUP_ASUS_GU605_SPI_SPEAKER2_TO_DAC1),

Now we need to apply the SSDT overlay.

[atimofeev]

Not sure if this an ideal solution or not, but this works for me.
gu605c-spi-cs-gpio.asl:

/*
 * This is an SSDT file.
 */

DefinitionBlock ("", "SSDT", 2, "Cirrus", "CsGpios", 0x00001000)
{
    External (_SB_.PC00.SPI0, DeviceObj)
    External (_SB_.PC00.SPI0.SPK1, DeviceObj)

    Scope (_SB.PC00.SPI0)
    {
        Name (_DSD, Package ()
        {
            ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),

            Package ()
            {
                Package ()
                {
                    "cs-gpios",
                    Package ()
                    {
                        0,             // Native CS0
                        SPK1, 0, 0, 0, // first GPIO declared in SPK1
                    }
                },
            }
        })
    }
}

{
  pkgs,
  lib,
  ...
}:
let
  ssdt-gu605c-spi-cs-gpio-patch = pkgs.runCommand "ssdt-gu605c-spi-cs-gpio" { } ''
    mkdir iasl
    cp ${./gu605c-spi-cs-gpio.asl} iasl/gu605c-spi-cs-gpio.asl
    ${lib.getExe' pkgs.acpica-tools "iasl"} iasl/gu605c-spi-cs-gpio.asl

    mkdir -p kernel/firmware/acpi
    cp iasl/gu605c-spi-cs-gpio.aml kernel/firmware/acpi/
    find kernel | ${lib.getExe pkgs.cpio} -H newc --create > patched-acpi-tables.cpio

    cp patched-acpi-tables.cpio $out
  '';
in
{

  boot.initrd.prepend = [ (toString ssdt-gu605c-spi-cs-gpio-patch) ];

}

[atimofeev]

From what I understood in kernel bugzilla thread, we have to wait for fix in Asus BIOS to get rid of this patch.
Not sure if this should be included as hardware module or not, as this ACPI SSDT patch will be obsolete at some point in future.