Rolf Meeser wrote:

On 06/06/2011 01:44 PM, Clemens Ladisch wrote:

...

Many audio devices with multiple vendor-specific interfaces do not have a control interface. This code would split them into multiple cards.

Breaking existing setups would indeed be bad. Are that cards with audio interfaces not following the Audio Class spec?

Yes.

What would be the easiest way to identify them, so we could assign a new card index only in case of a compliant card?

Non-compliant devices don't have a control interface.

In theory, the USB core probes a device's interfaces in order, so the control interface usually is probed first. However, I'm not sure if this is really true for all devices. It's probably safest to check explicitly if the device has any interface marked as audio control 1/2.

Regards, Clemens