Implicit feedback on BOSS GT-1, the saga continues...

Thu Apr 8 05:08:53 CEST 2021

That sounds like a good test.  I'm building it with the patch you posted
earlier today, except pertaining to my Roland Boutique D-05 ID.  It will
take a while before I have the result, though.  Also, that
"snd_usb_audio.dyndbg=+p" is just a kernel boot (not build) option,
correct?:
I hope so, or I'll have to start the build over yet again. ;)

On Wed, Apr 7, 2021 at 9:48 PM Mike Oliphant <oliphant at nostatic.org> wrote:

> Hi Geraldo - I had the same thought and I have tried enabling playback
> feedback while turning off capture feedback without my endpoint patch. It
> doesn't work - at least not on the GT-1. Playback/capture fails to start.
>
> Speaking of testing, if you (or anyone else following this discussion) have
> one of these Roland/BOSS devices, it would be great if you could try
> testing with playback feedback enabled and my endpoint.c workaround.
>
> Mike
>
> On Wed, Apr 7, 2021 at 7:21 PM Geraldo Nascimento <
> geraldogabriel at gmail.com>
> wrote:
>
> > Thanks, Mike, one thing I can tell you right off the bat is that if you
> > turn implicit feedback sync on for both endpoints at the same time like
> you
> > mentioned, without your workaround inside endpoint.c, they most likely
> will
> > stall because they would both be waiting for each other to start.
> >
> > Have you tried engaging the generic implicit feedback sync just for the
> > playback, thereby commenting out the capture implicit feedback entries,
> and
> > re-enabling snd_usb_endpoint_implicit_feedback_sink(ep) inside
> endpoint.c?
> > Does playback still fail to start?
> >
> > If you choose to perform this simple test please share with us the test's
> > dyndbg logs right from the moment you turn on the device, not just after
> > you start jackd.
> >
> > Sorry for the endless do-this, do-that. Such is the pace of teledebugging
> >
> >
> > Em Qua, 7 de abr de 2021 21:38, Mike Oliphant <oliphant at nostatic.org>
> > escreveu:
> >
> >> Geraldo - here is the dmesg output when starting up jackd for
> >> capture/playback:
> >>
> >> With my patch:
> >>
> >> [  136.734081] usb 3-1.2: Open EP 0x8e, iface=2:1, idx=0
> >> [  136.734088] usb 3-1.2:   channels=2, rate=44100, format=S32_LE,
> >> period_bytes=256, periods=2, implicit_fb=0
> >> [  136.734092] usb 3-1.2: Setting usb interface 2:0 for EP 0x8e
> >> [  136.734233] usb 3-1.2: Setting usb interface 2:1 for EP 0x8e
> >> [  136.734381] usb 3-1.2: 2:1 Set sample rate 44100, clock 0
> >> [  136.734388] usb 3-1.2: Setting params for data EP 0x8e, pipe 0x70480
> >> [  136.734394] usb 3-1.2: Set up 12 URBS, ret=0
> >> [  136.734466] usb 3-1.2: Open EP 0xd, iface=1:1, idx=0
> >> [  136.734468] usb 3-1.2:   channels=2, rate=44100, format=S32_LE,
> >> period_bytes=256, periods=2, implicit_fb=1
> >> [  136.734471] usb 3-1.2: Reopened EP 0x8e (count 1)
> >> [  136.734473] usb 3-1.2: Setting usb interface 1:0 for EP 0xd
> >> [  136.734605] usb 3-1.2: Setting usb interface 1:1 for EP 0xd
> >> [  136.734762] usb 3-1.2: 1:1 Set sample rate 44100, clock 0
> >> [  136.734774] usb 3-1.2: Setting params for data EP 0xd, pipe 0x68400
> >> [  136.734781] usb 3-1.2: Set up 12 URBS, ret=0
> >> [  136.734830] usb 3-1.2: Starting data EP 0xd (running 0)
> >> [  136.734873] usb 3-1.2: 12 URBs submitted for EP 0xd
> >> [  136.734876] usb 3-1.2: Starting data EP 0x8e (running 0)
> >> [  136.734906] usb 3-1.2: 12 URBs submitted for EP 0x8e
> >> [  136.740627] usb 3-1.2: Starting data EP 0x8e (running 1)
> >> [  136.740634] usb 3-1.2: 2:1 Start Capture PCM
> >> [  136.740635] usb 3-1.2: 1:1 Start Playback PCM
> >>
> >>
> >> With the unpatched kernel:
> >>
> >> [  344.813203] usb 3-1.2: Open EP 0x8e, iface=2:1, idx=0
> >> [  344.813210] usb 3-1.2:   channels=2, rate=44100, format=S32_LE,
> >> period_bytes=256, periods=2, implicit_fb=1
> >> [  344.813213] usb 3-1.2: Open EP 0xd, iface=1:1, idx=0
> >> [  344.813215] usb 3-1.2:   channels=2, rate=44100, format=S32_LE,
> >> period_bytes=256, periods=2, implicit_fb=0
> >> [  344.813217] usb 3-1.2: Setting usb interface 2:0 for EP 0x8e
> >> [  344.813367] usb 3-1.2: Setting usb interface 2:1 for EP 0x8e
> >> [  344.813494] usb 3-1.2: 2:1 Set sample rate 44100, clock 0
> >> [  344.813503] usb 3-1.2: Setting params for data EP 0x8e, pipe 0x70580
> >> [  344.813509] usb 3-1.2: Set up 12 URBS, ret=0
> >> [  344.813513] usb 3-1.2: Setting usb interface 1:0 for EP 0xd
> >> [  344.813587] usb 3-1.2: Setting usb interface 1:1 for EP 0xd
> >> [  344.813758] usb 3-1.2: 1:1 Set sample rate 44100, clock 0
> >> [  344.813765] usb 3-1.2: Setting params for data EP 0xd, pipe 0x68500
> >> [  344.813770] usb 3-1.2: Set up 2 URBS, ret=0
> >> [  344.813858] usb 3-1.2: Reopened EP 0xd (count 1)
> >> [  344.813883] usb 3-1.2: Starting data EP 0xd (running 0)
> >> [  344.813899] usb 3-1.2: 2 URBs submitted for EP 0xd
> >> [  344.819499] usb 3-1.2: Starting data EP 0x8e (running 0)
> >> [  344.819532] usb 3-1.2: 12 URBs submitted for EP 0x8e
> >> [  344.819535] usb 3-1.2: Starting data EP 0xd (running 1)
> >> [  344.819538] usb 3-1.2: 2:1 Start Capture PCM
> >> [  344.819540] usb 3-1.2: 1:1 Start Playback PCM
> >> [  344.820663] usb 3-1.2: Stopping data EP 0xd (running 2)
> >> [  344.820688] usb 3-1.2: Stopping data EP 0x8e (running 1)
> >> [  344.820693] usb 3-1.2: 2:1 Stop Capture PCM
> >> [  344.820695] usb 3-1.2: Stopping data EP 0xd (running 1)
> >> [  344.820697] usb 3-1.2: 1:1 Stop Playback PCM
> >> [  344.833799] usb 3-1.2: Starting data EP 0xd (running 0)
> >> [  344.833852] usb 3-1.2: 2 URBs submitted for EP 0xd
> >> [  344.833867] usb 3-1.2: Starting data EP 0x8e (running 0)
> >> [  344.833888] usb 3-1.2: 12 URBs submitted for EP 0x8e
> >> [  344.833890] usb 3-1.2: Starting data EP 0xd (running 1)
> >> [  344.833891] usb 3-1.2: 2:1 Start Capture PCM
> >> [  344.833893] usb 3-1.2: 1:1 Start Playback PCM
> >>
> >> On Wed, Apr 7, 2021 at 1:30 PM Geraldo Nascimento <
> >> geraldogabriel at gmail.com> wrote:
> >>
> >>> Em Qua, 7 de abr de 2021 17:16, Mike Oliphant <oliphant at nostatic.org>
> >>> escreveu:
> >>>
> >>>> Hi Geraldo - I don't have that patch applied, but it shouldn't make
> any
> >>>> behavioral difference - it just seems to be simplifying the code.
> >>>>
> >>>
> >>> Point taken.
> >>>
> >>>
> >>>> The issue is that the BOSS GT-1 *does* need implicit feedback on
> >>>> playback to avoid clock timing issues, and the current behavior is
> >>>> disabling that feedback.
> >>>>
> >>>
> >>> Mike, would you mind posting some dyndbg logs for both the stock
> >>> behaviour and your endpoint.c/generic quirk modified behaviour?
> >>>
> >>> Just add snd_usb_audio.dyndbg=+p to your kernel options and please
> share
> >>> the logs.
> >>>
> >>>
> >>>> Mike
> >>>>
> >>>> On Wed, Apr 7, 2021 at 1:04 PM Geraldo Nascimento <
> >>>> geraldogabriel at gmail.com> wrote:
> >>>>
> >>>>> Hey Mike, did you catch the latest patch by Takashi Iwai for capture
> >>>>> quirky devices?
> >>>>>
> >>>>> You can find it here:
> >>>>>
> https://patchwork.kernel.org/project/alsa-devel/patch/20210406113837.32041-1-tiwai@suse.de/
> >>>>>
> >>>>> Em Qua, 7 de abr de 2021 16:55, Mike Oliphant <oliphant at nostatic.org
> >
> >>>>> escreveu:
> >>>>>
> >>>>>> I had thought that the recent implicit feedback changes were fully
> >>>>>> working
> >>>>>> on the BOSS GT-1, but it turns out that I just hadn't tested well
> >>>>>> enough.
> >>>>>>
> >>>>>> Audio playback and capture works, but with periodic dropouts. I get
> >>>>>> the
> >>>>>> exact same behavior as I did with the quirk to completely disable
> >>>>>> implicit
> >>>>>> feedback. Without the implicit feedback, you get dropouts from clock
> >>>>>> drift
> >>>>>> - how bad probably varies from card to card. On mine it is every
> >>>>>> second or
> >>>>>> so.
> >>>>>>
> >>>>>> If I switch playback feedback for the GT-1 to generic by doing
> >>>>>> "IMPLICIT_FB_GENERIC_DEV(0x0582, 0x01d6)", I get the previous old
> >>>>>> behavior,
> >>>>>> which is that playback completely fails to start.
> >>>>>>
> >>>>>> With generic playback feedback, and using my previous patch to
> >>>>>> endpoint.c
> >>>>>> to avoid playback waiting on capture mentioned here:
> >>>>>>
> >>>>>>
> >>>>>>
> https://mailman.alsa-project.org/pipermail/alsa-devel/2020-January/161951.html
> >>>>>>
> >>>>>> playback and capture work perfectly for me.
> >>>>>>
> >>>>>
>

-- 
Protect your digital freedom and privacy, eliminate DRM, learn more at
http://www.defectivebydesign.org/what_is_drm
On a related note, also see https://www.fsf.org/campaigns/surveillance