Attempts to open serial port created by drivers qcserial & usbserial fails

[Viktors Petrovs]

Binary package hint: linux-image-2.6.31-4-generic

Attempts to open serial port created by drivers qcserial & usbserial fails with dmesg message:
qcserial ttyUSB0: usb_serial_generic_open - failed resubmitting read urb, error -22

---
Release: 9.10, Ubuntu karmic (development branch)
Kernel: 2.6.31-4-generic

System:
HP Compaq Mini 701en
built-in HP un2400 Mobile Broadband Module (based on Qualcomm Gobi chipset)
Hardware ID's:
#1 03f0:201d Hewlett-Packard (While firmware is not loaded)
#2 03f0:1f1d Hewlett-Packard (Same device with firmware loaded)

What i have done:
---
1) Loaded kernel module "hp-wmi". Device with id #1 apears. (as expected)
2) Loaded kernel module "qcserial". Driver founds device and brings up serial port /dev/ttyUSB0. (as expected)

dmesg output:
-------------------
usb 1-6: new high speed USB device using ehci_hcd and address 7
usb 1-6: configuration #1 chosen from 1 choice
qcserial 1-6:1.2: Qualcomm USB modem converter detected
usb 1-6: Qualcomm USB modem converter now attached to ttyUSB0

3) Trying to load firmware into serial port /dev/ttyUSB0 results in error. Port can't be opened!
Firmware loader used: http://www.codon.org.uk/~mjg59/gobi_loader

dmesg output:
-------------------
qcserial ttyUSB0: usb_serial_generic_open - failed resubmitting read urb, error -22

4) Recompiled usbserial kernel module with patch applied (using 2.6.31-4-generic):
http://www.kernel.org/diff/diffview.cgi?file=%2Fpub%2Flinux%2Fkernel%2Fv2.6%2Fsnapshots%2Fpatch-2.6.31-rc4-git3.bz2;z=142

5) Recompiled qcserial kernel module with patch applied: (using 2.6.31-4-generic. Another issue, see patch.)
http://www.spinics.net/lists/linux-usb/msg20203.html

6) After restart i can use serial port created by qcserial driver & download firmware to device. (as expected)
7) After firmware is loaded, new device with id #2 apears (old device id #1 is replaced with id #2). (as expected)
8) qcserial driver registers new device as serial port & network-manager picks it up as modem device. (as expected)
9) All done, i can connect to internet using my 3G Mobile Broadband Modem.

Information used:
http://ubuntuforums.org/showthread.php?t=1008200
http://www.codon.org.uk/~mjg59/gobi_loader/
http://www.spinics.net/lists/linux-usb/msg18632.html
http://www.kernel.org/diff/diffview.cgi?file=%2Fpub%2Flinux%2Fkernel%2Fv2.6%2Fsnapshots%2Fpatch-2.6.31-rc4-git3.bz2;z=142

[Viktors Petrovs (viks77)]

After upgrade to linux-image-2.6.31-5-generic no more kernel module recompilations needed.