Re: [PATCH] usb-core: Add MS_INTR_BINTERVAL USB quirk

From: Alan Stern
Date: Sun Mar 12 2017 - 21:31:20 EST


On Sun, 12 Mar 2017, Dave Mielke wrote:

> [quoted lines by Alan Stern on 2017/03/12 at 17:18 -0400]
>
> >Interesting. This is a high-speed device that mistakenly uses the
> >low/full-speed encoding for an interrupt bInterval value?
>
> Yes.
>
> >That's pretty unusual. Most HID devices (which includes the Braille
> >devices I have heard of) run at low speed, and a few of them run at
> >full speed. I can't remember any running at high speed.
>
> According to my collection of data, 5 say 1.00, 15 say 1.1, and 21 say 2.0.

A device's speed is only partially related to its USB version. A
USB-1.1 device can run at low speed or full speed. A USB-2 device can
run at low, full, or high speed. And a USB-3 device can run at low,
full, high, or Super speed.

Alan Stern