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

[Andrew Morton <akpm@linux-foundation.org>]

On Sun, 22 Jun 2008 11:42:53 -0700 Greg KH <greg@kroah.com> wrote:

> 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?
> 

Also, lots of things have been fixed since 2.6.26-rc2 - there might be
benefit in retesting 2.6.26-rc7.

And can you tell us whether this is new behaviour?  Was 2.6.25 OK?

Thanks.