What is wrong with FreeBSD and USB Support

Hans Petter Selasky hps at selasky.org
Mon Mar 6 11:31:26 UTC 2017


On 03/06/17 11:53, Markus Rechberger wrote:
> 1. slow usb control messages - did you already noticed that?

 From what I can see no USB control transfer completed no later than 
1.555 milliseconds. I loaded the numbers in the trace into a spreadsheet 
and got the attached distribution.

This is not slow. What times do you expect?

The fastest XHCI can do is ~ 0.125 ms and from the analysis is appears 
that the USB device is NAKing a little bit, causing the extra delay.


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