Bug#497925: linux-image-2.6.26-1-686: WARNING: at drivers/usb/serial/usb-serial.c:320 serial_write_room+0x41/0x4d [usbserial]

[Winfried Tilanus <winfried@tilanus.com>]

Package: linux-image-2.6.26-1-686
Version: 2.6.26-4
Severity: normal

On my thinkpad x61s laptop, I get several times: 

WARNING: at drivers/usb/serial/usb-serial.c:320 serial_write_room+0x41/0x4d [usbserial]()

in dmesg after powercycling the Sierra Wireless MC8775 UMTS-card two
times. Scenario to reproduce:

[card is active after boot]

echo disable > /proc/acpi/ibm/wan

[ttyUSB0-2 disconnect, at second 112 in attached dmseg]

echo enable > /proc/acpi/ibm/wan

[ttyUSB0-2 connect, at second 182 in attached dmesg]
[normal ppp operation of card]

echo disable > /proc/acpi/ibm/wan

[ttyUSB0-2 disconnect, at second 217 in attached dmseg]

echo enable > /proc/acpi/ibm/wan

[ttyUSB0-2 connect, at second 226 in attached dmesg]

After this dmesg shows 16 warnings at usb-serial.c. Dispite the 
warnings, the UMTS-card seems to operate normal.

-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)

Kernel: Linux 2.6.26-1-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

-- debconf information excluded