[libusb] libusb couldn't open USB device /sys/bus/usb/devices/1-2/001/002

[Pankaj C. <pan...@se...>]

Hi,
       I am trying to run libusb-1.0.21 in my router with kernel
version-3.10.14 for my usb dongle .As this version of kernel ,there is no
/proc/bus/usb or /dev/bus/usg, so I am giving a path as a path=
"/sys/bus/usb/devices/1-2" but I am not able to open the usb device.
Below is the log with loglevel=4

[timestamp] [threadID] facility level [function call] <message>
--------------------------------------------------------------------------------
[ 0.000080] [0000212a] libusb: debug [libusb_init] created default context
[ 0.000220] [0000212a] libusb: debug [libusb_init] libusb v1.0.21.11156
[ 0.000560] [0000212a] libusb: debug [find_usbfs_path] found usbfs at
/sys/bus/usb/devices/1-2
[ 0.000680] [0000212a] libusb: debug [op_init] bulk continuation flag
supported
[ 0.000700] [0000212a] libusb: debug [op_init] zero length packet flag
supported
[ 0.000860] [0000212a] libusb: debug [op_init] sysfs can relate devices
[ 0.000920] [0000212a] libusb: debug [op_init] sysfs has complete
descriptors
[ 0.001240] [0000212b] libusb: debug [linux_netlink_event_thread_main]
netlink event thread entering

[ 0.001360] [0000212a] libusb: debug [linux_get_device_address] getting
address for device: 1-2 detached: 0
[ 0.001380] [0000212a] libusb: debug [linux_get_device_address] scan 1-2
[ 0.001740] [0000212a] libusb: debug [linux_get_device_address] bus=1 dev=2
[ 0.001780] [0000212a] libusb: debug [linux_enumerate_device] busnum 1
devaddr 2 session_id 258
[ 0.001820] [0000212a] libusb: debug [linux_enumerate_device] allocating
new device for 1/2 (session 258)
[ 0.002120] [0000212a] libusb: debug [linux_get_parent_info] parent_dev
usb1 not enumerated yet, enumerating now

[ 0.002180] [0000212a] libusb: debug [linux_get_device_address] getting
address for device: usb1 detached: 0
[ 0.002220] [0000212a] libusb: debug [linux_get_device_address] scan usb1
[ 0.002460] [0000212a] libusb: debug [linux_get_device_address] bus=1 dev=1
[ 0.002500] [0000212a] libusb: debug [linux_enumerate_device] busnum 1
devaddr 1 session_id 257
[ 0.002540] [0000212a] libusb: debug [linux_enumerate_device] allocating
new device for 1/1 (session 257)
[ 0.002720] [0000212a] libusb: debug [linux_get_parent_info] Dev 0x424278
(1-2) has parent 0x424740 (usb1) port 2

[ 0.002860] [0000212a] libusb: debug [linux_get_device_address] getting
address for device: usb1 detached: 0
[ 0.002900] [0000212a] libusb: debug [linux_get_device_address] scan usb1
[ 0.003100] [0000212a] libusb: debug [linux_get_device_address] bus=1 dev=1
[ 0.003120] [0000212a] libusb: debug [linux_enumerate_device] busnum 1
devaddr 1 session_id 257
[ 0.003160] [0000212a] libusb: debug [linux_enumerate_device] session_id
257 already exists

[ 0.003280] [0000212a] libusb: debug [linux_get_device_address] getting
address for device: usb2 detached: 0
[ 0.003320] [0000212a] libusb: debug [linux_get_device_address] scan usb2
[ 0.003520] [0000212a] libusb: debug [linux_get_device_address] bus=2 dev=1
[ 0.003560] [0000212a] libusb: debug [linux_enumerate_device] busnum 2
devaddr 1 session_id 513
[ 0.003580] [0000212a] libusb: debug [linux_enumerate_device] allocating
new device for 2/1 (session 513)
[ 0.003900] [0000212a] libusb: debug [usbi_add_pollfd] add fd 7 events 1
[ 0.003980] [0000212a] libusb: debug [usbi_io_init] using timerfd for
timeouts
[ 0.004060] [0000212a] libusb: debug [usbi_add_pollfd] add fd 9 events 1
Look for target devices ...
[ 0.004120] [0000212a] libusb: debug [libusb_get_device_list]
[ 0.004180] [0000212a] libusb: debug [libusb_get_device_descriptor]
[ 0.004220] [0000212a] libusb: debug [libusb_get_device_descriptor]
[ 0.004320] [0000212a] libusb: debug [libusb_get_device_descriptor]
 No devices in target mode or class found
Look for default devices ...
[ 0.004400] [0000212a] libusb: debug [libusb_get_device_list]
[ 0.004440] [0000212a] libusb: debug [libusb_get_device_descriptor]
[ 0.004460] [0000212a] libusb: debug [libusb_get_device_descriptor]
   product ID matched
[ 0.004500] [0000212a] libusb: debug [libusb_get_device_descriptor]
 Found devices in default mode (1)
Access device 002 on bus 001
[ 0.004580] [0000212a] libusb: debug [libusb_open] open 1.2

[ 0.004760] [0000212a] libusb: error [_get_usbfs_fd] File doesn't exist,
wait 10 ms and try again
[ 0.680160] [0000212a] libusb: error [_get_usbfs_fd] libusb couldn't open
USB device /sys/bus/usb/devices/1-2/001/002: No such file or directory
[ 0.680260] [0000212a] libusb: debug [op_open] open failed with no device,
but device still attached
[ 0.680480] [0000212a] libusb: debug [libusb_open] open 1.2 returns -4
Error opening the device. Abort

[ 0.680520] [0000212a] libusb: debug [libusb_exit]
[ 0.680560] [0000212a] libusb: debug [libusb_exit] destroying default
context
[ 0.680600] [0000212a] libusb: debug
[libusb_handle_events_timeout_completed] doing our own event handling
[ 0.680640] [0000212a] libusb: debug [handle_events] poll fds modified,
reallocating
[ 0.680680] [0000212a] libusb: debug [handle_events] poll() 2 fds with
timeout in 0ms
[ 0.680700] [0000212a] libusb: debug [handle_events] poll() returned 1
[ 0.680740] [0000212a] libusb: debug [handle_events] caught a fish on the
event pipe
[ 0.680760] [0000212a] libusb: debug [handle_events] hotplug message
received
[ 0.680800] [0000212a] libusb: debug [handle_events] poll() 2 fds with
timeout in 0ms
[ 0.680840] [0000212a] libusb: debug [handle_events] poll() returned 0
[ 0.680880] [0000212a] libusb: debug [usbi_remove_pollfd] remove fd 7
[ 0.680960] [0000212a] libusb: debug [usbi_remove_pollfd] remove fd 9
[ 0.681060] [0000212b] libusb: debug [linux_netlink_event_thread_main]
netlink event thread exiting