[alsa-devel] [PATCH 3/3] ALSA: usb-audio: Integrate native DSD support for ITF-USB based DACs.

[Takashi Iwai]

On Fri, 23 Mar 2018 11:21:13 +0100,
Nobutaka Okabe wrote:
> 
> Integrate the native DSD support quirk codes of "ITF-USB DSD" based DACs.
> 
> Now, "is_itf_usb_dsd_2alts_dac()" and "is_itf_usb_dsd_3alts_dac()" is integrated
> into one function "is_itf_usb_dsd_dac()".
> So, remove the logic to distinguish UD-501 and UD-501V2 by the "Product Name".
> 
> The integration is possible by changing the following two functions.
> 
> - snd_usb_select_mode_quirk():
> Change the determination condition of the DSD mode switch command,
> from the altset number being used, to the audio format being played.
> Actually, this operation is same as playback using ASIO driver in Windows environment.
> 
> - snd_usb_interface_dsd_format_quirk():
> To which altset supports native DSD is determined by the number of altsets.
> Previously, it's a constant "2" or "3".
> 
> Signed-off-by: Nobutaka Okabe <nob77413 at gmail.com>

Applied to for-next branch, but with a minor fix about the comment
style below...

> -		if (fp->altsetting == 3)
> +		/* Altsetting 2 support native DSD if the num of altsets is three (0-2),
> +		   Altsetting 3 support native DSD if the num of altsets is four (0-3). */

Use the standard comment style mentioned in submitting-patches.rst at
the next time.  Also, it'd be better to fold lines in a bit narrower
(less than 75 chars) in the changelog text.  I formatted by myself at
this time.

The code change itself is good and a nice cleanup.


Thanks!

Takashi