Comment 13 for bug 43686

i'm having this issue without the hang problem using jpilot.

seems that it has something to do with visor and usbserial modules

[17181737.352000] drivers/usb/serial/visor.c: USB HandSpring Visor / Palm OS driver
[17181748.448000] hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...
[17181748.448000] usb 1-1: USB disconnect, address 2
[17181748.448000] visor ttyUSB0: Handspring Visor / Palm OS converter now disconnected from ttyUSB0
[17181748.448000] visor ttyUSB1: Handspring Visor / Palm OS converter now disconnected from ttyUSB1
[17181748.448000] visor 1-1:1.0: device disconnected
[17181748.560000] usb 1-1: new full speed USB device using uhci_hcd and address 3
[17181748.680000] usb 1-1: device descriptor read/64, error -71
[17181748.904000] usb 1-1: device descriptor read/64, error -71
[17181749.120000] usb 1-1: new full speed USB device using uhci_hcd and address 4
[17181749.240000] usb 1-1: device descriptor read/64, error -71
[17181749.464000] usb 1-1: device descriptor read/64, error -71
[17181749.736000] usb 1-1: new full speed USB device using uhci_hcd and address 5
[17181750.152000] usb 1-1: device not accepting address 5, error -71
[17181750.264000] usb 1-1: new full speed USB device using uhci_hcd and address 6
[17181750.672000] usb 1-1: device not accepting address 6, error -71
[17181775.400000] usb 1-1: new full speed USB device using uhci_hcd and address 7
[17181775.544000] visor 1-1:1.0: Handspring Visor / Palm OS converter detected
[17181775.544000] usb 1-1: Handspring Visor / Palm OS converter now attached to ttyUSB0
[17181775.544000] usb 1-1: Handspring Visor / Palm OS converter now attached to ttyUSB1
[17181776.704000] Unable to handle kernel NULL pointer dereference at virtual address 00000094
[17181776.704000] printing eip:
[17181776.704000] e0fc4778
[17181776.704000] *pde = 00000000
[17181776.704000] Oops: 0000 [#1]
[17181776.704000] PREEMPT SMP
[17181776.704000] Modules linked in: visor usbserial snd_rtctimer ip_conntrack_irc ip_conntrack_ftp ipt_state ipt_limit ipt_LOG ip_conntrack nfnetlink binfmt_misc bnep rfcomm l2cap bluetooth i810 drm ppdev acpi_sbs i2c_acpi_ec dev_acpi ac video hotkey tc1100_wmi pcc_acpi battery sony_acpi button container ipt_TCPMSS ipt_tcpmss iptable_filter ip_tables pppoe pppox ipv6 af_packet ppp_generic slhc deflate zlib_deflate twofish serpent aes blowfish des sha256 sha1 crypto_null af_key md_mod dm_mod tun eeprom i2c_i801 dell_rbu snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_seq_device lp 8139too mii joydev tsdev parport_pc pcmcia parport yenta_socket rsrc_nonstatic pcmcia_core floppy hw_random serio_raw shpchp pci_hotplug pcspkr psmouse snd_intel8x0 snd_ac97_codec snd_ac97_bus snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd soundcore snd_page_alloc i2c_i810 i2c_algo_bit i2c_core intel_agp agpgart evdev ext3 jbd ide_generic uhci_hcd usbcore ide_cd cdrom ide_disk piix generic thermal processor fan capability commoncap vga16fb vgastate fbcon tileblit font bitblit softcursor
[17181776.704000] CPU: 0
[17181776.704000] EIP: 0060:[<e0fc4778>] Not tainted VLI
[17181776.704000] EFLAGS: 00010246 (2.6.15-27-686)
[17181776.704000] EIP is at serial_chars_in_buffer+0x18/0xa0 [usbserial]
[17181776.704000] eax: d28cd000 ebx: 00000000 ecx: 00000000 edx: c508caa0
[17181776.704000] esi: d28cd000 edi: c9513f50 ebp: c73fc180 esp: c9513e9c
[17181776.704000] ds: 007b es: 007b ss: 0068
[17181776.704000] Process jpilot (pid: 5248, threadinfo=c9512000 task=d6492ab0)
[17181776.704000] Stack: d28cd940 c013d8dd d28cd001 d28cd000 00000000 c02479b8 d28cd000 d28cd940
[17181776.704000] c9513f50 d28cd000 c73fc180 00000000 d28cd00c c0243433 d28cd000 c73fc180
[17181776.704000] c9513f50 c73fc180 00000800 0000000b 00000015 c018a0a8 c73fc180 c9513f50
[17181776.704000] Call Trace:
[17181776.704000] [<c013d8dd>] add_wait_queue+0x1d/0x50
[17181776.704000] [<c02479b8>] normal_poll+0xe8/0x145
[17181776.704000] [<c0243433>] tty_poll+0x73/0xa0
[17181776.704000] [<c018a0a8>] do_select+0x1a8/0x370
[17181776.704000] [<c030f375>] schedule_timeout+0x55/0xc0
[17181776.704000] [<c0189d20>] __pollwait+0x0/0xd0
[17181776.704000] [<c018a506>] sys_select+0x256/0x400
[17181776.704000] [<c0103417>] sysenter_past_esp+0x54/0x75
[17181776.704000] Code: 16 df eb d6 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 90 53 83 ec 10 8b 0d 84 bd fc e0 8b 44 24 18 85 c9 8b 98 94 09 00 00 75 1f <8b> 83 94 00 00 00 85 c0 74 3d 8b 03 8b 40 04 89 5c 24 18 8b 88
[17181776.704000]