On a resume, when the power is lost during hibernate, the USB core will call hub_reset_resume for the xHCI USB 2.0 roothub, but not for the USB 3.0 roothub: [ 164.748310] usb usb1: root hub lost power or was reset [ 164.748353] usb usb2: root hub lost power or was reset [ 164.748487] usb usb3: root hub lost power or was reset [ 164.748488] xhci_hcd 0000:01:00.0: Stop HCD ... [ 164.870039] hub 4-0:1.0: hub_resume ... [ 164.870054] hub 3-0:1.0: hub_reset_resume This causes issues later, because the USB core assumes the USB 3.0 hub attached to the USB 3.0 roothub is still active. It attempts to queue a control URB for the external hub, which fails because all the device slot contexts were released when the USB 3.0 roothub lost power: [ 164.980044] hub 4-1:1.0: hub_resume [ 164.980047] xhci_hcd 0000:01:00.0: Get port status returned 0x10101 [ 164.980049] xHCI xhci_urb_enqueue called with unaddressed device [ 164.980053] hub 3-0:1.0: port 1: status 0101 change 0001 [ 164.980056] hub 4-1:1.0: hub_port_status failed (err = -22) [ 164.980060] xhci_hcd 0000:01:00.0: `MEM_WRITE_DWORD(3'b000, 32'hffffc90008948440, 32'h202e1, 4'hf); [ 164.980062] xHCI xhci_urb_enqueue called with unaddressed device [ 164.980066] xhci_hcd 0000:01:00.0: clear port connect change, actual port 0 status = 0x2e1 [ 164.980069] hub 4-1:1.0: hub_port_status failed (err = -22) [ 164.980072] xhci_hcd 0000:01:00.0: get port status, actual port 1 status = 0x2a0 [ 164.980074] xHCI xhci_urb_enqueue called with unaddressed device [ 164.980077] xhci_hcd 0000:01:00.0: Get port status returned 0x100 [ 164.980079] hub 4-1:1.0: hub_port_status failed (err = -22) [ 164.980082] xHCI xhci_urb_enqueue called with unaddressed device [ 164.980085] hub 4-1:1.0: hub_port_status failed (err = -22) [ 164.980088] hub 4-1:1.0: port 4: status 0000 change 0000 [ 164.980091] xHCI xhci_urb_enqueue called with unaddressed device [ 164.980094] hub 4-1:1.0: activate --> -22 [ 164.980113] xHCI xhci_urb_enqueue called with unaddressed device [ 164.980117] hub 4-1:1.0: hub_port_status failed (err = -22) [ 164.980119] xHCI xhci_urb_enqueue called with unaddressed device [ 164.980123] hub 4-1:1.0: can't resume port 4, status -22 [ 164.980126] hub 4-1:1.0: port 4 status ffff.ffff after resume, -22 [ 164.980129] usb 4-1.4: can't resume, status -22 [ 164.980131] hub 4-1:1.0: logical disconnect on port 4 This causes issues when a USB 3.0 hard drive is attached to the external USB 3.0 hub when the system is hibernated: [ 6249.849653] sd 8:0:0:0: [sdb] Unhandled error code [ 6249.849659] sd 8:0:0:0: [sdb] Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK [ 6249.849663] sd 8:0:0:0: [sdb] CDB: Read(10): 28 00 00 00 2a 08 00 00 02 00 [ 6249.849671] end_request: I/O error, dev sdb, sector 10760 Make sure to inform the USB core that *both* xHCI roothubs lost power. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("khubd").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.