USB doesn't come back (usb 1-1: device descriptor read/64, error -110) !

I'm using Beaglebone black with 3.7v LiPo battery,
When I remove the power 5v supply some seconds and put it back on,
the USB port doesn't work again !

The errors :

usb 1-1: device descriptor read/64, error -110
usb 1-1: device not accepting address 2, error -110
INFO: task scsi_eh_0:81 blocked for more than 60 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Kernel panic - not syncing: hung_task: blocked tasks
[<c00114f1>] (unwind_backtrace+0x1/0x9c) from [<c04d0bdd>] (panic+0x59/0x15c)
[<c04d0bdd>] (panic+0x59/0x15c) from [<c007390d>] (watchdog+0x19d/0x1c0)
[<c007390d>] (watchdog+0x19d/0x1c0) from [<c00454a3>] (kthread+0x6b/0x78)
[<c00454a3>] (kthread+0x6b/0x78) from [<c000c8fd>] (ret_from_fork+0x11/0x34)

I have the same problem with USB mass storage or with a wifi key ...
Any ideas ?