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

Thu Apr 8 04:46:49 CEST 2021

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.
>>>>>>
>>>>>