I frequently find USB3 unreliable, on more than one PC (but not all).

Typical usage will be to take images of SD cards via a card reader or to access data from a hard disk via USB->SATA. Generally, it'll connect and be visible for a short while before erroring.

My current PC lists its controller as: Intel Corporation 100 Series/C230 Series Chipset Family USB 3.0 xHCI Controller (rev 31)

How do I go about diagnosing this? Is it likely to be the driver, the hardware, or the external devices?

syslog from most recent failure follows. On this occasion, I was connecting through an unpowered USB3 hub, but the problems are pretty typical regardless.

Nov 13 13:00:13 mark-ubuntu kernel: [ 4184.999569] usb 2-4.4: new SuperSpeed Gen 1 USB device number 4 using xhci_hcd Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.026221] usb 2-4.4: New USB device found, idVendor=1f75, idProduct=0621, bcdDevice= 0.36 Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.026227] usb 2-4.4: New USB device strings: Mfr=4, Product=5, SerialNumber=6 Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.026231] usb 2-4.4: Product: Ext. HDD Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.026236] usb 2-4.4: Manufacturer: Innostor Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.026239] usb 2-4.4: SerialNumber: 20030225 Nov 13 13:00:13 mark-ubuntu mtp-probe: checking bus 2, device 4: "/sys/devices/pci0000:00/0000:00:14.0/usb2/2-4/2-4.4" Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.293229] usb-storage 2-4.4:1.0: USB Mass Storage device detected Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.293858] scsi host4: usb-storage 2-4.4:1.0 Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.294091] usbcore: registered new interface driver usb-storage Nov 13 13:00:13 mark-ubuntu kernel: [ 4185.298900] usbcore: registered new interface driver uas Nov 13 13:00:32 mark-ubuntu kernel: [ 4203.492176] usb 2-4.4: device not accepting address 4, error -62 Nov 13 13:00:43 mark-ubuntu kernel: [ 4214.500585] usb 2-4.4: device not accepting address 4, error -62 Nov 13 13:00:48 mark-ubuntu kernel: [ 4220.136105] usb 2-4.4: Device not responding to setup address. Nov 13 13:00:48 mark-ubuntu kernel: [ 4220.344806] usb 2-4.4: device not accepting address 4, error -71 Nov 13 13:00:48 mark-ubuntu kernel: [ 4220.348168] usb 2-4-port4: cannot disable (err = -71) Nov 13 13:00:48 mark-ubuntu kernel: [ 4220.355169] usb 2-4-port4: cannot reset (err = -71) Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.798423] usb 2-4-port4: cannot reset (err = -71) Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.897949] usb 2-4-port4: cannot reset (err = -71) Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.901440] usb 2-4-port4: cannot reset (err = -71) Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.904914] usb 2-4-port4: cannot reset (err = -71) Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.904922] usb 2-4-port4: Cannot enable. Maybe the USB cable is bad? Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.908444] usb 2-4-port4: cannot disable (err = -71) Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.911947] usb 2-4-port4: cannot disable (err = -71) Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.972838] usb 2-4: USB disconnect, device number 2 Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.972843] usb 2-4.1: USB disconnect, device number 3 Nov 13 13:00:49 mark-ubuntu kernel: [ 4220.974004] usb 2-4.4: USB disconnect, device number 4 Nov 13 13:00:49 mark-ubuntu kernel: [ 4221.353012] usb 2-4: new SuperSpeed Gen 1 USB device number 5 using xhci_hcd Nov 13 13:00:49 mark-ubuntu kernel: [ 4221.376022] usb 2-4: New USB device found, idVendor=05e3, idProduct=0612, bcdDevice=92.24 Nov 13 13:00:49 mark-ubuntu kernel: [ 4221.376028] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 Nov 13 13:00:49 mark-ubuntu kernel: [ 4221.376032] usb 2-4: Product: USB3.0 Hub Nov 13 13:00:49 mark-ubuntu kernel: [ 4221.376036] usb 2-4: Manufacturer: GenesysLogic Nov 13 13:00:49 mark-ubuntu kernel: [ 4221.379203] hub 2-4:1.0: USB hub found

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