Ignored USB-audio implicit feedback in kernel 5.8rc3

[Pavel Hofman]

Dne 02. 07. 20 v 13:28 Pavel Hofman napsal(a):
> 
> 
> Please is the requirement that EP OUT + EP IN implicit feedback data
> must be in the same interface really necessary? If such a requirement
> was dropped, IMO many devices could be removed from the existing
> set_sync_ep_implicit_fb_quirk and many devices would work out of the
> box, 

I am still thinking about the single-interface requirement. If both
endpoints were to be part of a single interface, could they use
different altsettings for different sample lengths for capture and
playback? E.g. to save USB bandwidth when the capture is used only for
implicit feedback - capturing at 16bits, playback at 32bits.

In the quirked XMOS devices the common clock for both directions is
defined by the clock feature, the altsettings for each direction (in
separate interfaces) are used for setting sample length.

Thank you very much for any insight into the issue. IMO not having to
add quirks before a device starts working would be advantageous for all
involved.

Best regards,

Pavel.