[alsa-devel] USB asynchronous mode feedback format

[Alex Lee]

On Fri, 2010-10-15 at 16:24 +0200, Julian Scheel wrote:

> 
> Don't see any syncpipe related errors. Only thing I see is:
> usb 1-1.3: new full speed USB device using ehci_hcd and address 11
> 11:1:1: endpoint lacks sample rate attribute bit, cannot set.
> 11:1:1: endpoint lacks sample rate attribute bit, cannot set.
> 
> Does not seem to be feedback related... Although it would be nice to know, 
> what's wrong there?

You probably need to fix that sample rate attribute bit for rate
feedback to work.

It is in the bmAttribute of the 
	//Audio endpoint specific descriptor
#define AUDIO_EP_ATRIBUTES	UAC_EP_CS_ATTR_SAMPLE_RATE	 // sampling freq,
no pitch, no pading

#define AUDIO_EP_DELAY_UNIT	0x00	 	// Unused
#define AUDIO_EP_LOCK_DELAY	0x0000		// Unused

Alex