[Armadillo:07729] armadillo-420 usb cdc_acmのドライバが落ちる

[辻 泰裕]

初めて投稿させていただきます。
辻と申します。

armadillo-420で/dev/ttyACM0 を介して通信を行っている途中
でUSBを抜き取ると以下のようなメッセージが表示され、
その後、どのUSBも認識しなくなります。

-----------------------------------------------------------------------------
usb 2-1: USB disconnect, address 2
cdc_acm: acm_ctrl_irq - usb_submit_urb failed with result -19
fsl-ehci fsl-ehci.1: HC died; cleaning up
irq 37: nobody cared (try booting with the "irqpoll" option)
[<c02ee488>] (dump_stack+0x0/0x14) from [<c0070738>]
(__report_bad_irq+0x2c/0x98)
[<c007070c>] (__report_bad_irq+0x0/0x98) from [<c0070a9c>]
(note_interrupt+0x2f8/0x34c)
r4:c3c66000
[<c00707a4>] (note_interrupt+0x0/0x34c) from [<c007169c>]
(handle_level_irq+0x120/0x150)
[<c007157c>] (handle_level_irq+0x0/0x150) from [<c002a048>]
(__exception_text_start+0x48/0x60)
r7:c3c67e08 r6:c040fe88 r5:00000025 r4:c03cc6b0
[<c002a000>] (__exception_text_start+0x0/0x60) from [<c002a7a4>]
(__irq_svc+0x44/0x88)
Exception stack(0xc3c67d58 to 0xc3c67da0)
7d40: 00000025 c0037528
7d60: c3c66000 20000013 c3c66000 00000022 0000000a c040bcc0 00000001
00000000
7d80: c040e548 c3c67dcc c3c67dd0 c3c67da0 c004a81c c004a728 20000013
ffffffff
r7:00000104 r6:00250000 r5:fc400000 r4:ffffffff
[<c004a6dc>] (__do_softirq+0x0/0xe4) from [<c004a81c>] (irq_exit+0x5c/0x70)
[<c004a7c0>] (irq_exit+0x0/0x70) from [<c002a04c>]
(__exception_text_start+0x4c/0x60)
r4:c03cc6b0
[<c002a000>] (__exception_text_start+0x0/0x60) from [<c002a7a4>]
(__irq_svc+0x44/0x88)
Exception stack(0xc3c67e08 to 0xc3c67e50)
7e00: 00000001 a0000013 c03ca424 00000000 00000000 00000000
7e20: c0407805 c3c67ee4 00000026 c3c66000 c03ca478 c3c67ecc c03ca418
c3c67e50
7e40: c003f664 c0045704 60000013 ffffffff
r7:00000002 r6:00250000 r5:fc400000 r4:ffffffff
[<c0045470>] (vprintk+0x0/0x3f4) from [<c02ee5ec>] (printk+0x1c/0x28)
[<c02ee5d0>] (printk+0x0/0x28) from [<c01ac3f0>] (usb_disconnect+0x4c/0x11c)
r3:00000002 r2:c2f354ec r1:c0389678 r0:c0387760
[<c01ac3a4>] (usb_disconnect+0x0/0x11c) from [<c01acf70>]
(hub_thread+0x2c0/0x10ec)
[<c01accb0>] (hub_thread+0x0/0x10ec) from [<c005b5e4>] (kthread+0x58/0x8c)
[<c005b58c>] (kthread+0x0/0x8c) from [<c00484e0>] (do_exit+0x0/0x6ec)
r7:00000000 r6:00000000 r5:00000000 r4:00000000
handlers:
[<c01ae8e8>] (usb_hcd_irq+0x0/0xac)
Disabling IRQ #37
-----------------------------------------------------------------------------

ccd_acmドライバがエラーを認識し、落ちていると思われますがなにか解決方法は
ないでしょうか？
通信（ポートのオープン？）を行っていない場合は、抜き差ししても大丈夫です。

原因、アドバイスよろしくお願い致します。