Comment 72 for bug 1314556

I'm having the same problem with both my 2012 Nexus 7 and my HTC One M8.

If I connect the device, I get the error message "Unable to mount Android Phone: Unable to open MTP device '[usb:005,120]'" for my HTC One M8. The message changes to "Unable to mount Nexus 7" when I plug the Nexus 7 in. The '[usb:005,120]' identifier also changes.

(All of the following was done with the HTC phone...)

But here's the interesting part: if I run "lsusb" with the error message on the screen, the device is detected one ID higher. Right now, "lsusb" is showing "Bus 005 Device 121: ID 0bb4:061a HTC (High Tech Computer Corp.)" for the phone. Using "ls -l /dev/bus/usb/X/Y" gives:

$ ls -l /dev/bus/usb/005/120
ls: cannot access /dev/bus/usb/005/120: No such file or directory
$ ls -l /dev/bus/usb/005/121
crw-rw----+ 1 root audio 189, 632 Jan 15 20:59 /dev/bus/usb/005/121

dmesg gives the following:

$ dmesg
[ 3202.628185] usb 5-2: new high-speed USB device number 122 using xhci_hcd
[ 3202.650762] usb 5-2: New USB device found, idVendor=0bb4, idProduct=061a
[ 3202.650769] usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 3202.650773] usb 5-2: Product: Android Phone
[ 3202.650777] usb 5-2: Manufacturer: HTC
[ 3202.653957] usb-storage 5-2:1.2: USB Mass Storage device detected
[ 3202.654251] scsi11 : usb-storage 5-2:1.2
[ 3202.796549] usb 5-2: USB disconnect, device number 122
[ 3203.576177] usb 5-2: new high-speed USB device number 123 using xhci_hcd
[ 3203.598656] usb 5-2: New USB device found, idVendor=0bb4, idProduct=061a
[ 3203.598663] usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 3203.598667] usb 5-2: Product: Android Phone
[ 3203.598670] usb 5-2: Manufacturer: HTC

(I've deleted the 'SerialNumber' lines; I don't know if they're sensitive or not)

Another time I tried to reproduce the dmesg output, I got:

[ 3271.638047] xhci_hcd 0000:08:00.0: xHCI xhci_drop_endpoint called with disabled ep ffff88056c19e040
[ 3271.638049] xhci_hcd 0000:08:00.0: xHCI xhci_drop_endpoint called with disabled ep ffff88056c19e000
[ 3271.638051] xhci_hcd 0000:08:00.0: xHCI xhci_drop_endpoint called with disabled ep ffff88057ad043c0
[ 3271.638052] xhci_hcd 0000:08:00.0: xHCI xhci_drop_endpoint called with disabled ep ffff88056c19e080
[ 3271.638053] xhci_hcd 0000:08:00.0: xHCI xhci_drop_endpoint called with disabled ep ffff88057ad041c0
[ 3271.638055] xhci_hcd 0000:08:00.0: xHCI xhci_drop_endpoint called with disabled ep ffff88057ad04380
[ 3271.638056] xhci_hcd 0000:08:00.0: xHCI xhci_drop_endpoint called with disabled ep ffff88057ad04180

I don't know if that's related. It doesn't always appear in dmesg.

I'm actually using Linux Mint, as follows:

$ uname -a
Linux roger-pc 3.13.0-39-generic #66-Ubuntu SMP Tue Oct 28 13:30:27 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
$ lsb_release -a
No LSB modules are available.
Distributor ID: LinuxMint
Description: Linux Mint 17 Qiana
Release: 17
Codename: qiana
$ lsb_release -au
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04 LTS
Release: 14.04
Codename: trusty