1 .\" $NetBSD: ehci.4,v 1.8 2001/11/21 17:22:56 augustss Exp $
3 .\" Copyright (c) 2001 The NetBSD Foundation, Inc.
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6 .\" This code is derived from software contributed to The NetBSD Foundation
7 .\" by Lennart Augustsson.
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30 .\" $FreeBSD: head/share/man/man4/ehci.4 232507 2012-03-04 16:59:45Z eadler $
37 .Nd USB Enhanced Host Controller driver
43 driver provides support for the
45 Enhanced Host Controller Interface,
51 controllers are peculiar in that they can only handle the
54 This means that they normally have one or more companion controllers
59 handling USB 1.x devices.
62 connector is electrically connected to two
65 The handling of this is totally automatic,
66 but can be noticed since
70 2.0 devices plugged in to the same
71 connector appear to connect to different USB busses.
80 device driver first appeared in
83 When the kernel has been compiled with
84 .Cd options USB_DEBUG ,
85 some tunables become available that affect the behavior of
87 These tunables can be set at the
89 prompt before booting the kernel or stored in
91 .Bl -tag -width "xxxxxx"
92 .It Va hw.usb.ehci.lostintrbug
93 This tunable enables the lost interrupt quirk.
94 The default value is 0 (off).
95 .It Va hw.usb.ehci.iaadbug
96 This tunable enables the EHCI doorbell quirk.
97 The default value is 0 (off).
98 .It Va hw.usb.ehci.no_hs
99 This tunable disables USB devices to attach like HIGH-speed ones and will force
100 all attached devices to attach to the FULL- or LOW-speed companion controller.
101 The default value is 0 (off).