> Enabling SOF interrupts will be a big pain :-) Well, enabling the
> interrupt itself is a no-brainer, but it'll cause terrible CPU overload.
Oh, I see. Hmm... would it be possible to allow upper levels to config this
dynamically ? I.e. for the ALSA subsystem there is no need for the SOF
timest
> >> I guess UAC1 doesn't need feedback endpoints, right? Seems like that
> >> should be something specific to UAC2. At least for now.
> >
> > It seems like it is needed there aswell, see
> > http://www.usb.org/developers/docs/devclass_docs/audio10.pdf (3.7.2.2)
> > (Feedback endpoint == Synch Endp
> I guess UAC1 doesn't need feedback endpoints, right? Seems like that
> should be something specific to UAC2. At least for now.
It seems like it is needed there aswell, see
http://www.usb.org/developers/docs/devclass_docs/audio10.pdf (3.7.2.2)
(Feedback endpoint == Synch Endpoint)
Regards
/R
> >> Indeed, that's also mandated by USB spec. Seems like we need to patch
> >> f_uac2.c. Can you check if setting the IN endpoint as implicit feedback
> >> data is enough?
> >
> > Just tried your proposed patches on 4.15.1 (with an RPi Zero) and with
> > g_audio, unfortunately there is no change.
Hi Felipe,
> Indeed, that's also mandated by USB spec. Seems like we need to patch
> f_uac2.c. Can you check if setting the IN endpoint as implicit feedback
> data is enough?
Just tried your proposed patches on 4.15.1 (with an RPi Zero) and with g_audio,
unfortunately there is no change. Device
> > Yes, but that isn't the issue AFAIU ? In the USB 2.0 standard related
> > to synchronization
> > (http://sdphca.ucsd.edu/lab_equip_manuals/usb_20.pdf chapter 5.12.4),
> > an isochronous OUT ep with asynchronous synchronization is *required*
> > (at least by Microsoft) to have a feedback IN ep,
> > It seems such a feedback endpoint is now required by the standard:
> > "The USB 2.0 specification states that if isochronous OUT data
> > endpoint uses the asynchronous synchronization, an isochronous
> > feedback endpoint is needed."
>
> We actually have both EP IN and EP OUT on the UAC2 func
Hi all,
I'm trying to get my head around how the UAC2 gadget stuff is supposed to work
in relation to sample rate conversion etc. etc. From the docs
(https://www.kernel.org/doc/htmldocs/gadget/structure.html), I surmise that:
1. USB controller driver
2. Gadget Driver
3. Upper Level (u_audio.c)
> >
> > 4.9 is over a year old, can you try 4.14, or even better yet, 4.15?
Just to confirm, I've tried with 4.14.18 (latest from
https://github.com/raspberrypi/firmware), and the problem remains.
Regards
/R
N�r��yb�X��ǧv�^�){.n�+{��^n�r���z���h�&�� �G���h�(�階�ݢj"���m��
> "Wait, never mind – I recognize that failing status code. usbaudio2.sys is
> complaining that you have an asynchronous data OUT endpoint but it can’t
> find a corresponding feedback endpoint."
>
> Unfortunately I have no idea what that means. Yet 😊 , but putting it out there
> in case someone el
> > Kernel version is 4.9.68 (https://github.com/raspberrypi/linux ,
> > commit d5a3b4cab0c8eacc93e58cfa1bdbd259399caedd), the wTotalLength
> > calc error is present in latest version also
> >
> (https://github.com/torvalds/linux/blob/master/drivers/usb/gadget/functio
> n/f_uac2.c#L219)
>
> 4.9 is
> We don't do github pull requests for the kernel, please see the long
> text response in that request for how to do it properly.
>
> Heck, we don't even use github :)
I know, found it out the hard way 😉
>
> > However, that wasn't enough. The device still isn't loaded properly.
>
> What do you
ign
ln -s configs/c.1 os_desc
#udevadm settle -t 5 || :
ls /sys/class/udc/ > UDC
-
Best regards
/Robert Bielik
Ps. Apologies if this isn't the correct forum for these kinds of questions.
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
13 matches
Mail list logo
