Re: 2.6.26-rc2 WARNING from usb-serial, and then my gps is dead

[Greg KH <greg@kroah.com>]

On Sun, Jun 22, 2008 at 08:22:03PM +0200, Helge Hafting wrote:
> This is what I got:
> ------------[ cut here ]------------
> WARNING: at drivers/usb/serial/usb-serial.c:306 serial_write+0x62/0x89 
> [usbserial]()
> Modules linked in: pl2303 usbserial sbs sbshc coretemp piix pcmcia ata_piix 
> iTCO_wdt ata_generic bay hci_usb intel_agp
> Pid: 10, comm: events/1 Tainted: G        W 2.6.26-rc2-hh1 #1
>
> Call Trace:
>  [<ffffffff80236b54>] warn_on_slowpath+0x51/0x7a
>  [<ffffffff8022c207>] __wake_up+0x38/0x4f
>  [<ffffffff8024565c>] __queue_work+0x23/0x33
>  [<ffffffff802456c8>] queue_work+0x37/0x40
>  [<ffffffffa0045fa3>] :pl2303:pl2303_write+0xf2/0x101
>  [<ffffffffa003c368>] :usbserial:serial_write+0x62/0x89
>  [<ffffffff803a8e81>] tty_put_char+0x2b/0x2d
>  [<ffffffff803ad3ca>] echo_char+0x47/0x60
>  [<ffffffff803ade97>] n_tty_receive_buf+0x2b4/0xd76
>  [<ffffffff8020a87e>] __switch_to+0xa2/0x396
>  [<ffffffff8023028d>] hrtick_set+0x88/0xf6
>  [<ffffffff80590b44>] thread_return+0x70/0xb4
>  [<ffffffff8023f013>] lock_timer_base+0x26/0x4c
>  [<ffffffff803a9abd>] flush_to_ldisc+0xf8/0x185
>  [<ffffffff803a99c5>] flush_to_ldisc+0x0/0x185
>  [<ffffffff8024520b>] run_workqueue+0x80/0x112
>  [<ffffffff80245afe>] worker_thread+0xd9/0xe8
>  [<ffffffff80248380>] autoremove_wake_function+0x0/0x2e
>  [<ffffffff80245a25>] worker_thread+0x0/0xe8
>  [<ffffffff80248264>] kthread+0x47/0x73
>  [<ffffffff802318c1>] schedule_tail+0x28/0x5d
>  [<ffffffff8020cf88>] child_rip+0xa/0x12
>  [<ffffffff8024821d>] kthread+0x0/0x73
>  [<ffffffff8020cf7e>] child_rip+0x0/0x12
>
> ---[ end trace 656e180042992f9e ]---
> I looked at the dmesg log because I have had lots of trouble with my gps 
> lately. I first suspected the cable, but then I saw this.
>
> After this, I have to restart gpsd, and perhaps replug the cable to get
> things going again. Until it happens again. This is a 64-bit dualcore 
> laptop.

Ick, that's not nice.

Can you enable debugging for the usb-serial core:
	echo 1 > /sys/module/usbserial/parameters/debug

and then run whatever program you were running that causes this warning
and then send us the kernel log?

thanks,

greg k-h