kernel error

Jul  6 09:55:44 localhost kernel: [ 5379.401513] BUG: sleeping function called from invalid context at kernel/mutex.c:94
Jul  6 09:55:44 localhost kernel: [ 5379.401526] in_atomic(): 1, irqs_disabled(): 1, pid: 400, name: X
Jul  6 09:55:44 localhost kernel: [ 5379.401540] Pid: 400, comm: X Not tainted 2.6.31.6-36.1.moblin2-ivi #1
Jul  6 09:55:44 localhost kernel: [ 5379.401547] Call Trace:
Jul  6 09:55:44 localhost kernel: [ 5379.401570]  [<c1022bb0>] __might_sleep+0xdc/0xe3
Jul  6 09:55:44 localhost kernel: [ 5379.401585]  [<c14677c9>] mutex_lock+0x18/0x32
Jul  6 09:55:44 localhost kernel: [ 5379.401598]  [<c11ea11f>] tty_unthrottle+0x11/0x3b
Jul  6 09:55:44 localhost kernel: [ 5379.401618]  [<f8329603>] ppp_asynctty_receive+0x412/0x41a [ppp_async]
Jul  6 09:55:44 localhost kernel: [ 5379.401632]  [<c11eb886>] flush_to_ldisc+0xf1/0x17f
Jul  6 09:55:44 localhost kernel: [ 5379.401645]  [<c11eb955>] tty_flip_buffer_push+0x41/0x51
Jul  6 09:55:44 localhost kernel: [ 5379.401680]  [<f84bfbba>] ftdi_process_read+0x42a/0x57d [ftdi_sio]
Jul  6 09:55:44 localhost kernel: [ 5379.401711]  [<f84bfedc>] ftdi_read_bulk_callback+0x1cf/0x1df [ftdi_sio]
Jul  6 09:55:44 localhost kernel: [ 5379.401727]  [<c12ecefc>] usb_hcd_giveback_urb+0x63/0x97
Jul  6 09:55:44 localhost kernel: [ 5379.401740]  [<c12fbfec>] ehci_urb_done+0xb6/0xc5
Jul  6 09:55:44 localhost kernel: [ 5379.401752]  [<c12fd6bb>] qh_completions+0x34a/0x3cd
Jul  6 09:55:44 localhost kernel: [ 5379.401764]  [<c12fd7e8>] ehci_work+0xaa/0x76e
Jul  6 09:55:44 localhost kernel: [ 5379.401779]  [<c1046ce7>] ? __hrtimer_start_range_ns+0x2c0/0x2cb
Jul  6 09:55:44 localhost kernel: [ 5379.401792]  [<c1300e51>] ehci_irq+0x166/0x18d
Jul  6 09:55:44 localhost kernel: [ 5379.401805]  [<c12ecb66>] usb_hcd_irq+0x27/0x5d
Jul  6 09:55:44 localhost kernel: [ 5379.401820]  [<c1061dea>] handle_IRQ_event+0x6c/0x13c
Jul  6 09:55:44 localhost kernel: [ 5379.401832]  [<c106331e>] handle_level_irq+0x77/0xbf
Jul  6 09:55:44 localhost kernel: [ 5379.401845]  [<c1004cf5>] handle_irq+0x3b/0x46
Jul  6 09:55:44 localhost kernel: [ 5379.401857]  [<c1004494>] do_IRQ+0x40/0x9b
Jul  6 09:55:44 localhost kernel: [ 5379.401869]  [<c1003029>] common_interrupt+0x29/0x30