Re: [PATCH] ALSA: usb-audio: Add native DSD quirks for PureAudio DAC series

[Takashi Iwai <tiwai@suse.de>]

On Fri, 14 Nov 2025 06:20:53 +0100,
Lushih Hsieh wrote:
> 
> The PureAudio APA DAC and Lotus DAC5 series are USB Audio
> 2.0 Class devices that support native Direct Stream Digital (DSD)
> playback via specific vendor protocols.
> 
> Without these quirks, the devices may only function in standard
> PCM mode, or fail to correctly report their DSD format capabilities
> to the ALSA framework, preventing native DSD playback under Linux.
> 
> This commit adds new quirk entries for the mentioned DAC models
> based on their respective Vendor/Product IDs (VID:PID), for example:
> 0x16d0:0x0ab1 (APA DAC), 0x16d0:0xeca1 (DAC5 series), etc.
> 
> The quirk ensures correct DSD format handling by setting the required
> SNDRV_PCM_FMTBIT_DSD_U32_BE format bit and defining the DSD-specific
> Audio Class 2.0 (AC2.0) endpoint configurations. This allows the ALSA
> DSD API to correctly address the device for high-bitrate DSD streams,
> bypassing the need for DoP (DSD over PCM).
> 
> Test on APA DAC and Lotus DAC5 SE under Arch Linux.
> 
> Tested-by: Lushih Hsieh <bruce@mail.kh.edu.tw>
> 
> Signed-off-by: Lushih Hsieh <bruce@mail.kh.edu.tw>

Thanks, applied now.


Takashi