Re: [RFC PATCH 0/5] USB Audio Gadget refactoring

From: Ruslan Bilovol
Date: Tue Jul 26 2016 - 17:22:40 EST


On Tue, Jul 26, 2016 at 11:06 AM, Clemens Ladisch <clemens@xxxxxxxxxx> wrote:
> Ruslan Bilovol wrote:
>> On Fri, Jul 15, 2016 at 10:43 AM, Clemens Ladisch <clemens@xxxxxxxxxx> wrote:
>>>>> On Tue, May 24, 2016 at 2:50 AM, Ruslan Bilovol
>>>>> <ruslan.bilovol@xxxxxxxxx> wrote:
>>>>>> it may break current usecase for some people
>>>
>>> And what are the benefits that justify breaking the kernel API?
>>
>> Main limitation with current f_uac1 design is - it can be used only on systems
>> with real ALSA card present and can have only exact number of
>> channels / sampling rate as sink card has. [...]
>> A real cases when it's required to have UAC1 gadget represented as virtual
>> sound card on gadget side: [...]
>
> Thanks.
>
>> Of course disadvantage of new approach for UAC1 gadget is you need to
>> use some userspace application for routing audio from virtual to real
>> sound card, like in case of UAC2 gadget. But thanks to existing
>> applications like alsaloop it's not difficult nowadays.
>
> I don't know what the maintainer will say, but you would increase the
> chances of this change being accepted when you show a concrete example
> of how to change the userspace configuration from the old to the new
> driver. (And add it to the documentation.)

Good point, need to update documentation in next files (make similar to UAC2):
Documentation/usb/gadget-testing.txt
Documentation/ABI/testing/configfs-usb-gadget-uac1

Best regards,
Ruslan