Dennis HilkLinux diagnosticsDE

USB controllers & peripherals

USB hub class

A hub is both an upstream USB function and the branching point for downstream devices.

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On this page
  1. Overview & identity
  2. Driver & binding
  3. Firmware
  4. Read-only diagnostics
  5. Limitations & related issues
  6. References

Overview & identity

The hub class 09 can be declared at device or interface level. A hub entry identifies topology; it does not uniquely identify an enclosure, docking station or the electronics behind every port.

This is an explicit class, transport or driver-context profile. It is not an exact numeric product match.

A numeric match establishes a candidate family within the reviewed evidence. Marketing names, board variants, subsystem conditions and successful operation remain separate questions.

Driver & binding

The hub binding is implemented inside usbcore, rather than by a standalone hub module, and matches both forms of the class descriptor. Follow port paths in lsusb -t to associate disconnects with an upstream branch; downstream interfaces remain independently bound.

  • usbcore — kernel driver/module candidate

Detected, bound, operational: learn the difference

Firmware

Device/revision dependent

No external firmware filename was established in the checked driver path. This does not describe firmware stored inside the device.

Inspect firmware packaging on your distribution

Read-only diagnostics

Run one displayed command at a time. Replace uppercase placeholders with the affected device, interface or module from your own output. Commands are never executed here. Read-only output can still contain private identifiers.

Inspect interfaces and negotiated speed

lsusb -t

This read-only usbutils query normally needs no sudo. Driver belongs to the displayed interface, while speed is the negotiated connection. Other interfaces of the same physical device may use other drivers.

Read one USB interface driver link

readlink /sys/bus/usb/devices/INTERFACE/driver

Replace INTERFACE with an existing interface such as 1-2:1.0, not only the whole-device name 1-2. This reads a symlink without sudo; a missing link leaves binding unconfirmed.

Limitations & related issues

A hub listing does not prove its power budget, negotiated charging mode or signal integrity. Several entries can be logical parts of one physical dock.

These guides are linked for relevant observations, not as known defects of every device in this family.

Choose a hardware diagnostic workflow · Inspect a log excerpt in Fix Lab

References

Source review records a checked implementation or document, not a reproduced hardware test. Version-specific tables do not establish a minimum kernel or guaranteed operation.