8 Nov
2007
8 Nov
'07
5:14 p.m.
Karsten Wiese wrote:
snd-usb-audio uses number_of_packets equalling multiples of 8 currently when transfering over USB 2.0, no? If so, with above patch that "multiples of 8"-thing could go away and snd-usb-audio could achieve up to 8 times less userspace-activation-jitter in low latency setups like 128 frames/period, 2 periods.
I'm using the 8-microframes alignment because ehci-hcd configures the controller to interrupt at most every 1 ms. It has a module option to change this, but as long as snd-usb-audio cannot detect a lower setting, it would not make sense to allow shorter periods.
Regards, Clemens