Re: [PATCH] ALSA: usb-audio: Re-read descriptors for Xiaomi 2717:d005

[Takashi Iwai <tiwai@suse.de>]

On Wed, 23 Sep 2026 17:25:52 +0200,
Xucheng Pan wrote:
> 
> The Xiaomi 2717:d005 USB audio transmitter supports Sound 2 Pro and
> Sound 2 Max speakers. This issue was reproduced with two Sound 2 Pro
> speakers paired in stereo. After a USB replug, Linux detects the
> transmitter and exposes a hardware volume control, but moving the volume
> slider changes neither the audible level nor the speakers' volume LEDs.
> Windows controls the same speakers with its in-box USB Audio driver.
> USB captures show standard UAC2 volume SET_CUR requests on both systems.
> 
> Re-reading the device descriptor (18 bytes), configuration header
> (9 bytes), and full configuration descriptor (184 bytes on the tested
> unit) after 2717:d005 is configured restores hardware volume control.
> The USBFS sequence recovered the device after multiple replug tests.
> Reading only the device descriptor did not restore volume control.
> 
> Perform these reads when snd-usb-audio first probes 2717:d005. Use the
> configuration header's wTotalLength for the final read. If a read fails,
> warn and continue probing so that playback remains available.
> 
> Tested on 7.2.6-zen2-1-zen with the existing userspace workaround
> disabled. After a physical USB replug, the quirk ran when 2717:d005
> appeared, and both audible volume and the speakers' LEDs followed the
> KDE volume slider.
> 
> Signed-off-by: Xucheng Pan <panxucc@gmail.com>

Applied to for-next branch now.  Thanks.


Takashi