HUBD(4D) Devices HUBD(4D)

NAME

hubd - USB hub driver

SYNOPSIS

hub@unit-address

DESCRIPTION

The hubd is a USBA (illumos USB Architecture) compliant client driver
that supports USB hubs conforming to the Universal Serial Bus
Specification 3.0. The hubd driver supports bus-powered and self-
powered hubs. The driver supports hubs with individual port power,
ganged power and no power switching.


When a device is attached to a hub port, the hubd driver enumerates
the device by determining its type and assigning an address to it.
For multi-configuration devices, hubd sets the preferred
configuration (refer to cfgadm_usb(8) to select a configuration). The
hubd driver attaches a driver to the device if one is available for
the default or selected configuration. When the device is
disconnected from the hub port, the hubd driver offlines any driver
instance attached to the device.

FILES

/kernel/drv/hubd
32- bit x86 ELF kernel module


/kernel/drv/amd64/hubd
64- bit x86 ELF kernel module


/kernel/drv/sparcv9/hubd
64-bit SPARC ELF kernel module

ATTRIBUTES

See attributes(7) for a description of the following attributes:


+---------------+-------------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-------------------------------+
|Architecture | SPARC, x86, PCI-based systems |
+---------------+-------------------------------+

SEE ALSO

usba(4D), attributes(7), cfgadm_usb(8)


Writing Device Drivers


Universal Serial Bus Specification 2.0


System Administration Guide: Basic Administration

DIAGNOSTICS

In addition to being logged, the following messages may also appear
on the system console. Messages are formatted in the following
manner:

WARNING: <device path> <hubd<instance number>): Message...


where <instance number> is the instance number of hubd and <device
path> is the physical path to the device in /devices directory.
Messages from the root hub are displayed with a usb<instance number>
prefix instead of hub<instance number> as the root hub is an
integrated part of the host controller.

Connecting device on port <number> failed.

The driver failed to enumerate the device connected on port
<number> of hub. If enumeration fails, disconnect and re-connect.


Use of a USB 1.0 hub behind a high speed port may cause unexpected
failures.

Devices connected to a USB 1.0 hub which are in turn connected to
an external USB 2.0 hub, may misbehave unexpectedly or suddenly
go offline. This is due to a documented incompatibility between
USB 1.0 hubs and USB 2.0 hub Transaction Translators. Please use
only USB 2.0 or USB 1.1 hubs behind high-speed ports.


Connecting a high speed device to a non-high speed hub (port x) will
result in a loss of performance. Please connect the device to a high
speed port to get the maximum performance.

USB 2.0 devices connected to USB 1.0 or 1.1 hubs cannot run at
their highest speed, even when the hub is in turn connected to a
high-speed port. For best performance, reconnect without going
through a USB 1.0 or 1.1 hub.


Cannot access <device>. Please reconnect.

This hub has been disconnected because a device other than the
original one has been inserted. The driver informs you of this
fact by displaying the name of the original device.


Port <n> overcurrent.

An overcurrent condition was detected. Please remove the device
on this port.


Devices not identical to the previous one on this port. Please
disconnect and reconnect.

Same condition as described above; however in this case, the
driver is unable to identify the original device with a name
string.


Hub driver supports max of <n> ports on hub. Hence, using the first
<number of physical ports> of <n> ports available.

The current hub driver supports hubs that have <n> ports or less.
A hub with more than <n> ports has been plugged in. Only the
first <n> out of the total <number of physical ports> ports are
usable.


Hub global over current condition, please disconnect the devices
connected to the hub to clear the condition. You may need to re-
connect the hub if the ports do not work.

An overcurrent condition was detected on the hub. This means that
the aggregate current being drawn by the devices on the
downstream ports exceeds a preset value. Refer to section 7.2.1.2
and 11.13 of the Universal Serial Bus Specification 2.0. If this
message continues to display, you may need to remove downstream
devices to eliminate the problem. If any port does not work after
the overcurrent condition is cleared, re-connect the hub to re-
enable the ports.


Root hub over current condition, please check your system to clear
the condition as soon as possible. You may need to reboot the system
if the root hub does not recover automatically.

An overcurrent condition was detected on the root hub, indicating
that malfunctioning devices on the downstream ports are drawing
too much current. Please disconnect the problematic downstream
devices to eliminate the problem. If the root hub doesn't work
after the overcurrent condition is cleared, you may need to
reboot the system.


The following messages may be logged into the system log. They are
formatted in the following manner:

<device path><hubd<instance number>): message...


Local power has been lost, please disconnect hub.

A USB self-powered hub has lost external power. All USB devices
connected down-stream from this hub will cease to function.
Disconnect the hub, plug in the external power-supply and then
plug in the hub again.


Local power has been lost, the hub could draw <x> mA power from the
USB bus.

A USB self/bus-powered hub has lost external power. Some USB
devices connected down-stream from this hub may cease to
function. Disconnect the external power-supply and then plug in
the hub again.


Two bus-powered hubs cannot be concatenated.

A bus-powered hub was connected to a bus powered hub port. Please
remove this bus-powered hub and connect it to a self-powered hub
or a root hub port.


Configuration <n> for device <device> at port <m> exceeds power
available for this port. Please re-insert your device into another
hub port which has enough power.

The device requires more power than is available on this port.


Port <n> in over current condition, please check the attached device
to clear the condition. The system will try to recover the port, but
if not successful, you need to re-connect the hub or reboot the
system to bring the port back to work.

An overcurrent condition was detected on port <n>. This means the
device connected to the port is drawing more current than the hub
can supply. If this message continues to display, please
disconnect the device to eliminate the problem. If the port
doesn't work after the overcurrent condition is cleared, please
re-connect the hub or reboot the system to enable the port again.


Unable to attach USB 3.x hub <vendor> <device>. A maximum of 5 hubs
may be cascaded.

USB 3.0 has an upper bound on the number of hubs that may be
chained together. If this limit is exceeded, a hub may not be
detected or attached. The hub will be functional if plugged into
a different part of the USB topology. To determine the depth of
the hub, count the number of devices between it and the host
controller.

May 13, 2017 HUBD(4D)