What is wrong with FreeBSD and USB Support

[Markus Rechberger]

On Mon, Mar 6, 2017 at 12:30 PM, Hans Petter Selasky <hps at selasky.org> wrote:
> Hi,
>
> 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.
>

it's EHCI, but the driver needs 14 seconds to load everything with
freebsd (ok there's a lot to send) but the other systems are all way
faster with that (7 seconds max for initialising 4 chipsets). I
somewhat think that this issue also has to do with the bulk latency
killing the data transfer.
Maybe the actual send is quick but maybe there's some additional
libusb20 - usb userspace interface - usb - roundtrip problem that
causes this high latency.