I rebuilt with frame pointers and debug symbols. I see lots and lots of: .... usb 2-2: clear tt 1 (1042) error -71 usb 2-2: clear tt 1 (1042) error -71 usb 2-2: clear tt 1 (1042) error -71 usb 2-2: clear tt 1 (1042) error -71 usb 2-2: clear tt 1 (1042) error -71 usb 2-2: clear tt 1 (1042) error -71 usb 2-2.3: USB disconnect, address 14 Investigations continue... usb 2-2 is the hub to which the PL2303 is attached. I now see a similar traceback to before, not when I press the reset button, but when I remove the USB connector. pl2303 ttyUSB0: pl2303 converter now disconnected from ttyUSB0 pl2303 2-2.1:1.0: device disconnected BUG: unable to handle kernel NULL pointer dereference at 00000014 IP: [<c0149336>] __lock_acquire+0x91/0x12bf *pde = 00000000 Oops: 0000 [#1] PREEMPT SMP last sysfs file: /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/rfkill/rfkill 0/state Modules linked in: cdc_acm kvm_intel kvm kqemu cpufreq_powersave cpufreq_userspace cpufreq_conservative snd_hda_codec_si3054 snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_timer iwlagn snd uhci_hcd pl2303 usbserial iwlcore joydev wmi uvcvideo soundcore snd_page_alloc Pid: 7718, comm: minicom Not tainted (2.6.30-rc8 #20) HP Pavilion dv9700 Notebook PC EIP: 0060:[<c0149336>] EFLAGS: 00010046 CPU: 0 EIP is at __lock_acquire+0x91/0x12bf EAX: 00000046 EBX: 00000046 ECX: 00000010 EDX: 00000002 ESI: 00000000 EDI: 00000000 EBP: f48d3d00 ESP: f48d3c78 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process minicom (pid: 7718, ti=f48d2000 task=f4fe08c0 task.ti=f48d2000) Stack: f72875ac f4fe0c80 f4fe08c0 f4fe08c0 f48d3d18 00000046 00000002 00000000 00000000 00000010 f4fe08c0 00000000 00000002 00000000 00000000 f6066918 f4fe08c0 f4fe0c70 00000000 00000001 f4fe08c0 f4fe0c88 00000001 00000000 Call Trace: [<c014a617>] ? lock_acquire+0xb3/0xd6 [<f8628435>] ? pl2303_close+0x48/0x1af [pl2303] [<c04878c5>] ? _spin_lock_irqsave+0x39/0x49 [<f8628435>] ? pl2303_close+0x48/0x1af [pl2303] [<f8628435>] ? pl2303_close+0x48/0x1af [pl2303] [<c04861fc>] ? mutex_lock_nested+0x286/0x2a0 [<f80f7a21>] ? serial_close+0x86/0x12d [usbserial] [<c02e6a9d>] ? tty_release_dev+0x188/0x423 [<c0485ac4>] ? __mutex_unlock_slowpath+0xf0/0x111 [<c01487df>] ? trace_hardirqs_on_caller+0x103/0x124 [<c0485aed>] ? mutex_unlock+0x8/0xa [<f80f7998>] ? usb_serial_put+0x2b/0x2e [usbserial] [<f80f8010>] ? serial_open+0x1fd/0x209 [usbserial] [<c048770d>] ? _spin_unlock+0x27/0x3c [<c02e7206>] ? tty_open+0x2c0/0x38a [<c018fdaa>] ? chrdev_open+0x16b/0x183 [<c018c13d>] ? __dentry_open+0x146/0x23b [<c018c2cc>] ? nameidata_to_filp+0x2c/0x43 [<c018fc3f>] ? chrdev_open+0x0/0x183 [<c0196f55>] ? do_filp_open+0x3bd/0x6ee [<c013e85a>] ? __hrtimer_start_range_ns+0x220/0x22b [<c0289a45>] ? _raw_spin_unlock+0x78/0x7e [<c019e859>] ? alloc_fd+0xc8/0xd2 [<c018bf1c>] ? do_sys_open+0x44/0xc0 [<c01032a8>] ? sysenter_exit+0xf/0x1f [<c018bfda>] ? sys_open+0x1e/0x26 [<c010326f>] ? sysenter_do_call+0x12/0x3c Code: c0 00 0f 84 07 11 00 00 e9 cd 11 00 00 83 7d 98 07 76 0f e8 01 e2 13 00 68 62 0b 57 c0 e9 84 11 00 00 83 7d 98 00 75 0e 8b 4d 9c <8b> 59 04 85 db 0f 85 0e 03 00 00 8b 75 9c 83 3e 00 75 02 89 36 -- Dr Peter Chubb peter DOT chubb AT nicta.com.au http://www.ertos.nicta.com.au ERTOS within National ICT Australia Kernel Engineering Group (KEG): Where Systems Brew. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
