Re: [REGRESSION] Audient EVO4 hardware volume control now requires quirk

[Takashi Iwai <tiwai@suse.de>]

On Tue, 29 Sep 2026 00:39:05 +0200,
Sasha Levin wrote:
> 
> > [   80.940668] usb 3-1: cannot set ctl value: req = 0x1, wValue = 0x203,
> > wIndex = 0xa00, type = 4, data = 0x0/0x81
> [...]
> > numid=4,iface=MIXER,name='EVO4  Playback Volume'
> >    ; type=INTEGER,access=rw---R--,values=4,min=0,max=254,step=0
> >    : values=182,182,0,0
> 
> Thanks, that narrows it down.
> 
> Every failure is SET_CUR of the Volume control on feature unit 10, channel 3
> (wValue 0x0203, wIndex 0x0a00). That unit is 'EVO4  Playback Volume' and
> advertises read/write volume on all four channels. mixer_ctl_feature_put()
> writes channels 1 and 2, then returns the channel 3 error, so the hardware
> volume changes while userspace is told the write failed and adds software
> attenuation on top. Faaris sees the same on 7.3-rc5, so this is a mainline
> regression from 87a6f2fa6e6c ("ALSA: usb-audio: Propagate write errors in
> generic mixer put callbacks").

Right.  So a simple fix would be to just to set the IGNORE_CTL_ERROR
quirk flag like below.  One of iD14 models has already this flag, so
it might be safer to set to all Audient devices.


thanks,

Takashi

--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -2690,6 +2690,8 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
 		   QUIRK_FLAG_DSD_RAW),
 	DEVICE_FLG(0x2708, 0x0002, /* Audient iD14 */
 		   QUIRK_FLAG_IGNORE_CTL_ERROR),
+	DEVICE_FLG(0x2708, 0x0006, /* Audient EV04 */
+		   QUIRK_FLAG_IGNORE_CTL_ERROR),
 	DEVICE_FLG(0x2772, 0x0502, /* Musical Fidelity M6s DAC */
 		   0), /* for avoiding QUIRK_FLAG_DSD_RAW with vendor match */
 	DEVICE_FLG(0x2912, 0x30c8, /* Audioengine D1 */