[alsa-devel] snd-usb-audio syncronisation problem

[Adrian Stancu]

Yes!!! the feedback works correctly this way => perfect playback!

what I had to do was:
                [...]
                f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
                f /= 8;
                if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
                        spin_lock_irqsave(&subs->lock, flags);
                        subs->freqm = f;
                [...]

otherwise, the 'if' condition would still not be satisfied.
Words can not describe how thankful I am about this one!

Now, is there a way to incorporate this change into the driver without
affecting functionality for other usb audio devices?

On Fri, Feb 22, 2008 at 6:31 PM, Clemens Ladisch <clemens at ladisch.de> wrote:
> Adrian Stancu wrote:
>  > According to dmesg, the device is running at high speed:
>  > usb 1-6: new high speed USB device using ehci_hcd and address 20
>  >
>
> > So, if I convert the freq using the high speed formula, I get a value
>  > within the acceptable range,
>
>  No; the device is high speed, but it sends a full speed feedback value.
>
>  Please try "subs->freqm = f / 8;"
>
>
>  The value quoted in your previous message was exactly 48000 Hz; please
>  check if it ever changes.
>
>
>  Regards,
>  Clemens
>