Re: [PATCH] ALSA: hda - Add new driver for HDA controllers listed via ACPI

[Takashi Iwai <tiwai@suse.de>]

On Thu, 15 May 2025 15:31:46 +0200,
Daniel Dadap wrote:
> 
> Some systems expose HD-Audio controllers via objects in the ACPI tables
> which encapsulate the controller's interrupt and the base address for the
> HDA registers in an ACPI _CRS object, for example, as listed in this ACPI
> table dump excerpt:
> 
>         Device (HDA0)
>         {
>             Name (_HID, "NVDA2014")  // _HID: Hardware ID
>             ...
>             Name (_CRS, ResourceTemplate ()  // _CRS: Current Resource Settings
>             {
>                 Memory32Fixed (ReadWrite,
>                     0x36078000,         // Address Base
>                     0x00008000,         // Address Length
>                     )
>                 Interrupt (ResourceConsumer, Level, ActiveHigh, Exclusive, ,, )
>                 {
>                     0x0000021E,
>                 }
>             })
>         }
> 
> Add support for HDA controllers discovered through ACPI, including support
> for some platforms which expose such HDA controllers on NVIDIA SoCs. This
> is done with a new driver which uses existing infrastructure for extracting
> resource information from _CRS objects and plumbs the parsed resource
> information through to the existing HDA infrastructure to enable HD-Audio
> functionality on such devices.
> 
> Although this driver is in the sound/pci/hda/ directory, it targets devices
> which are not actually enumerated on the PCI bus. This is because it depends
> upon the Intel "Azalia" infrastructure which has traditionally been used for
> PCI-based devices.
> 
> Signed-off-by: Daniel Dadap <ddadap@nvidia.com>

Thanks for the patch.
The code looks fine.  Just a nitpicking:

> +static int __maybe_unused hda_acpi_suspend(struct device *dev)
....
> +static int __maybe_unused hda_acpi_resume(struct device *dev)

The __maybe_unused is superfluous when you set up
SYSTEM_SLEEP_PM_OPS() macro instead in the below:

> +static const struct dev_pm_ops hda_acpi_pm = {
> +	SET_SYSTEM_SLEEP_PM_OPS(hda_acpi_suspend, hda_acpi_resume)


thanks,

Takashi