Logitech Z10 USB speakers need a volume change before audio works

[Takashi Iwai]

On Wed, 01 Dec 2021 16:44:11 +0100,
Hans de Goede wrote:
> 
> Hi,
> 
> On 11/30/21 16:56, Takashi Iwai wrote:
> > On Tue, 30 Nov 2021 15:33:35 +0100,
> > Hans de Goede wrote:
> >>
> >> Hi,
> >>
> >> On 11/30/21 12:07, Hans de Goede wrote:
> >>> Hi,
> >>>
> >>> On 11/25/21 13:42, Takashi Iwai wrote:
> >>>> On Thu, 25 Nov 2021 12:04:41 +0100,
> >>>> Hans de Goede wrote:
> >>>>>
> >>>>> Hi,
> >>>>>
> >>>>> I've a set of Logitech Z10 USB speakers, which act as a USB soundcard.
> >>>>>
> >>>>> They have this weird glitch where after turning off my PC (and their
> >>>>> power-supply as well) and then turning things back on, they are silent
> >>>>> until I change the PCM volume control for the speakers inside
> >>>>> alsa-mixer.
> >>>>>
> >>>>> It seems like they need some "set-volume" command to be send over the
> >>>>> USB bus to unmute them when initially powered-up / turned on.
> >>>>>
> >>>>> Is their some existing usb-audio quirk which I can try to work around this?
> >>>>
> >>>> No such quirk is present for now.
> >>>>
> >>>> Was it tested with 5.16-rc?  There was a change in USB-audio driver
> >>>> initialization (commit b96681bd5827) and it might have some effect in
> >>>> your case.
> >>>
> >>> Yes I'm at 5.16-rc3 atm but I've been seeing this for quite some time.
> >>> I just never got around to reporting it. Mainly because I also never
> >>> got around to getting a bit clearer picture of the problem.
> >>>
> >>> I've spend some time this morning to get that clearer picture,
> >>> which was insightful.
> >>>
> >>>> Also, it's interesting to know whether it happens also once after
> >>>> suspend-resume, too.
> >>>
> >>> suspend-resume makes no difference, not even rebooting or
> >>> powering off the machine makes a difference.
> >>>
> >>> Once the speakers are in working order they stay in working order
> >>> until I turn off my machine; and then flick the power-switch on
> >>> the 240V AC power-bar which I use to power my laptop + dock +
> >>> monitors + the speakers and turn things back on the next morning.
> >>>
> >>> To be clear these speakers get their audio-data over USB
> >>> (as an usb-audio device) but they have their own power-supply
> >>> they are not USB powered. They also have a "soft" on/off button
> >>> which turns on/off the amplifier and LCD screen parts but leaves
> >>> the USB audio interface active.
> >>>
> >>> So I've been experimenting with reproducing the issue and I
> >>> need to do the following minimal steps to reproduce:
> >>>
> >>>  1. Unplug USB
> >>>  2. Unplug power
> >>>  3. Re-plug power
> >>>  4. Re-plug USB
> >>>  5. speaker-test -Dfront:CARD=Speaker,DEV=0 -S1
> >>>  6. Turn speakers on (with the on/off button on the speakers), no audio
> >>>
> >>>  5 and 6 may be swapped, same result
> >>>
> >>> And now that I have a reliable reproducer I've also been
> >>> playing with a reliable workaround which looks like this:
> >>>
> >>> 1. Start playing audio to the speakers
> >>> 2. Turn speakers on (with the on/off button on the speakers)
> >>> 3. Make a change to the 'PCM Playback Volume' ctrl
> >>>
> >>> Where 1. and 2. may be swapped. But the
> >>> 'PCM Playback Volume' ctrl change must be made while the
> >>> speakers are on and playing audio !
> >>>
> >>> Although I have found that this also works:
> >>>
> >>> 1. Start playing audio to the speakers
> >>> 2. Turn speakers on (with the on/off button on the speakers)
> >>> 3. Stop playing audio
> >>> 4. Make a change to the 'PCM Playback Volume' ctrl
> >>> 5. Start playing audio to the speakers again
> >>>
> >>> I then even here a brief "power-up buzz" coming from the
> >>> speakers at 4.
> >>>
> >>> And this sequence also works:
> >>>
> >>> 1. Start playing audio to the speakers
> >>> 2. Stop playing audio
> >>> 3. Turn speakers on (with the on/off button on the speakers)
> >>> 4. Make a change to the 'PCM Playback Volume' ctrl
> >>> 5. Start playing audio to the speakers again
> >>>
> >>> So it seems that to work (after having been unplugged
> >>> form the mains) these speakers need to:
> >>>
> >>> 1. Have had some audio send to them at least once
> >>> 2. After this have their 'PCM Playback Volume' ctrl poked
> >>>    at once while they are on (and if they are on cannot
> >>>    be seen from the PC side AFAICT).
> >>>
> >>> Note instead of changing the 'PCM Playback Volume' ctrl
> >>> toggling the associated mute ctrl works too.
> >>>
> >>> TL;DR: Since getting the speakers to work involves
> >>> setting a ctrl while they are on, which is something
> >>> which we cannot tell from the kernel side I don't believe
> >>> that there is anything we can do about this from within
> >>> the kernel.
> >>
> >> So thinking more about this I guess we could do something
> >> where we resend the last PCM volume to the device every
> >> 5 seconds *when the device is playing audio*, assuming that
> >> the resending of the same PCM volume is sufficient to fix
> >> things.
> >>
> >> These are pretty nice speakers so getting them to work without
> >> this glitch would be nice. But it would require a significant
> >> bit of (quirk enabled) code just for this 1 model speakers.
> >>
> >> Takashi, what do you think. Should I give the resend volume
> >> once every 5 seconds idea a try, or is it likely going to
> >> end up being too ugly to merge ?
> > 
> > It sounds too hackish and fragile to me...
> 
> Yes, I agree,
> 
> > Do we need to repeat each
> > 5 seconds?  Wouldn't it suffice to touch only once at setting up the
> > stream (or need before or after the stream start), instead?
> 
> The problem is that at least with my testing with alsamixer + speaker-test
> I need to make the PCM ctl change when the speakers are on.
> 
> And I often find myself doing the following:
> 
> 1. Start something which requires working audio
> 2. Oh wait, the speakers are off, turn them on
> 
> At which point if we do this at stream-start this would require
> a pause + unpause. At which point just hitting volume up + down
> hotkeys is just as easy (easier even when in say a video-conf-call).
> 
> So I believe my time is better spend to track down the pipewire
> regression where newer pipewire versions no longer use hw-volume-ctrl
> on these speakers for some reason. Fixing that will restore my old
> workaround and will hopefully also help other users.
> 
> I guess this is mostly an issue for me because I turn of the
> mains power to the speakers every evening, other users just
> need to fiddle with the volume once and then things will work
> until the speakers get unplugged from the mains.
> 
> > In anyway, alsa-info.sh output would be helpful.
> 
> Sure here you go:
> http://alsa-project.org/db/?f=8b93e72b6fb4be5c426eade5f78ed58137bdf0ef'
> 
> Note there are quite a few audio devices in my setup:
> 
> 1. My X1 carbon laptop's builtin sound
> 2. The Thunderbolt docks' USB audio (unused)
> 3. A TI USB audio codec going to the receiver connected to
> my proper/real speakers for listening music
> 4. The Logitech Z-10 speakers which we are discussing here
> 
> Anyway, not sure if this is worth spending much (more) time on
> but if you have some idea for me to test, let me know.

Below is a quick hack, let's see whether this kind of change is
enough for this device.


Takashi

--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -1280,6 +1280,15 @@ int snd_usb_apply_interface_quirk(struct snd_usb_audio *chip,
 				  int iface,
 				  int altno)
 {
+#ifdef CONFIG_PM
+	if (chip->usb_id == USB_ID(0x046d, 0x0a07)) {
+		struct usb_mixer_interface *mixer;
+		list_for_each_entry(mixer, &chip->mixer_list, list)
+			snd_usb_mixer_resume(mixer);
+		return 0;
+	}
+#endif
+
 	/* audiophile usb: skip altsets incompatible with device_setup */
 	if (chip->usb_id == USB_ID(0x0763, 0x2003))
 		return audiophile_skip_setting_quirk(chip, iface, altno);