On 07/26/2016 10:53 AM, Jassi Brar wrote: > On Tue, Jul 26, 2016 at 7:01 AM, Ruslan Bilovol > <ruslan.bilovol@xxxxxxxxx> 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. >> Yet it is not flexible - can't do audio processing between f_uac1 and the card. >> Also if someone wants to bind f_uac1 it to another sound card he has to >> unload g_audio or reconfigure it through configfs - that means USB >> reenumeration on host device. >> >> If you have a "virtual sound card", audio processing is done in userspace >> and is more flexible. You even don't need to have a real sound card and >> can use some userspace application for playing/capturing audio samples. >> Moreover, existing f_uac2 (that is USB Audio Class 2.0 function >> implementation) already uses approach of "virtual sound card" >> > While I agree the virtual sound card approach is the right way, I am > not sure if we should break the userspace api that the existing UAC1 > driver exposes. Maybe we should add another virtual-sound-card > exposing UAC1 driver ... and hopefully very similar to (or just port > of) the f_audio_source.c from android. Definitely agree with this opinion. I don't see any benefits of breaking the API here instead of adding just another USB function. Maybe even some pieces of code could be shared with f_uac1.c but I think that this should be a brand new function. Best regards, -- Krzysztof Opasiak Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
