[clug] Getting a USB modem to go ACM

[Doug Palmer]

I've been in the process of upgrading my system to shiny new hardware. 

One of the things that I am moving across is a D-Link DSB 560 USB modem.
To use the modem, I need to use the cdc-acm module, to get ACM working
so that I can access the modem on /dev/input/ttyACM0

This was working fine on my old system, running Fedora Core 2 with a
2.6.5 kernel, which produces a log of the form:

Sep 28 22:02:05 janus kernel: USB Universal Host Controller Interface
driver v2.2
Sep 28 22:02:05 janus kernel: uhci_hcd 0000:00:07.2: UHCI Host
Controller
Sep 28 22:02:05 janus kernel: uhci_hcd 0000:00:07.2: irq 193, io base
0000e000
Sep 28 22:02:05 janus kernel: uhci_hcd 0000:00:07.2: new USB bus
registered, assigned bus number 1
Sep 28 22:02:05 janus kernel: hub 1-0:1.0: USB hub found
Sep 28 22:02:05 janus kernel: hub 1-0:1.0: 2 ports detected
Sep 28 22:02:05 janus kernel: ehci_hcd 0000:00:0a.2: EHCI Host
Controller
Sep 28 22:02:05 janus kernel: ehci_hcd 0000:00:0a.2: irq 169, pci mem
22827000
Sep 28 22:02:05 janus kernel: ehci_hcd 0000:00:0a.2: new USB bus
registered, assigned bus number 2
Sep 28 22:02:05 janus kernel: ehci_hcd 0000:00:0a.2: USB 2.0 enabled,
EHCI 0.95, driver 2003-Dec-29
Sep 28 22:02:05 janus kernel: hub 2-0:1.0: USB hub found
Sep 28 22:02:05 janus kernel: hub 2-0:1.0: 5 ports detected
Sep 28 22:02:05 janus kernel: ohci_hcd 0000:00:0a.0: OHCI Host
Controller
Sep 28 22:02:05 janus kernel: ohci_hcd 0000:00:0a.0: irq 185, pci mem
2282f000
Sep 28 22:02:05 janus kernel: ohci_hcd 0000:00:0a.0: new USB bus
registered, assigned bus number 3
Sep 28 22:02:05 janus kernel: usb 1-1: new low speed USB device using
address 2
Sep 28 22:02:05 janus kernel: hub 3-0:1.0: USB hub found
Sep 28 22:02:05 janus kernel: hub 3-0:1.0: 3 ports detected
Sep 28 22:02:05 janus kernel: ohci_hcd 0000:00:0a.1: OHCI Host
Controller
Sep 28 22:02:06 janus kernel: ohci_hcd 0000:00:0a.1: irq 193, pci mem
22831000
Sep 28 22:02:06 janus kernel: ohci_hcd 0000:00:0a.1: new USB bus
registered, assigned bus number 4
Sep 28 22:02:06 janus kernel: input: USB HID v1.10 Mouse [Microsoft
Microsoft 5-Button Mouse with IntelliEye(TM)] on usb-0000:00:07.2-1
Sep 28 22:02:06 janus kernel: hub 4-0:1.0: USB hub found
Sep 28 22:02:06 janus kernel: hub 4-0:1.0: 2 ports detected
Sep 28 22:02:06 janus kernel: usb 4-1: new full speed USB device using
address 2Sep 28 22:02:06 janus kernel: usb 4-1: configuration #2 chosen
from 2 choices
Sep 28 22:02:06 janus kernel: cdc_acm 4-1:2.0: ttyACM0: USB ACM
device<6>usbcore: registered new driver cdc_acm
Sep 28 22:02:06 janus kernel: drivers/usb/class/cdc-acm.c: v0.23:USB
Abstract Control Model driver for USB modems and ISDN adapters

On the new system, which is also running Fedora Core 2, using kernel
2.6.7, I get:

Sep 27 22:40:04 fezzic kernel: ehci_hcd 0000:00:1d.7: USB 2.0 enabled,
EHCI 1.00, driver 2004-May-10
Sep 27 22:40:04 fezzic kernel: hub 1-0:1.0: USB hub found
Sep 27 22:40:04 fezzic kernel: hub 1-0:1.0: 8 ports detected
Sep 27 22:40:04 fezzic kernel: USB Universal Host Controller Interface
driver v2.2
Sep 27 22:40:04 fezzic kernel: ACPI: PCI interrupt 0000:00:1d.0[A] ->
GSI 16 (level, low) -> IRQ 16
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.0: UHCI Host
Controller
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.0: irq 16, io base
0000ef00
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.0: new USB bus
registered, assigned bus number 2
Sep 27 22:40:04 fezzic kernel: hub 2-0:1.0: USB hub found
Sep 27 22:40:04 fezzic kernel: hub 2-0:1.0: 2 ports detected
Sep 27 22:40:04 fezzic kernel: ACPI: PCI interrupt 0000:00:1d.1[B] ->
GSI 19 (level, low) -> IRQ 19
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.1: UHCI Host
Controller
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.1: irq 19, io base
0000ef20
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.1: new USB bus
registered, assigned bus number 3
Sep 27 22:40:04 fezzic kernel: hub 3-0:1.0: USB hub found
Sep 27 22:40:04 fezzic kernel: hub 3-0:1.0: 2 ports detected
Sep 27 22:40:04 fezzic kernel: ACPI: PCI interrupt 0000:00:1d.2[C] ->
GSI 18 (level, low) -> IRQ 18
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.2: UHCI Host
Controller
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.2: irq 18, io base
0000ef40
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.2: new USB bus
registered, assigned bus number 4
Sep 27 22:40:04 fezzic kernel: hub 4-0:1.0: USB hub found
Sep 27 22:40:04 fezzic kernel: hub 4-0:1.0: 2 ports detected
Sep 27 22:40:04 fezzic kernel: ACPI: PCI interrupt 0000:00:1d.3[A] ->
GSI 16 (level, low) -> IRQ 16
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.3: UHCI Host
Controller
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.3: irq 16, io base
0000ef80
Sep 27 22:40:04 fezzic kernel: uhci_hcd 0000:00:1d.3: new USB bus
registered, assigned bus number 5
Sep 27 22:40:04 fezzic kernel: hub 5-0:1.0: USB hub found
Sep 27 22:40:04 fezzic kernel: hub 5-0:1.0: 2 ports detected
Sep 27 22:40:04 fezzic kernel: usb 2-1: new full speed USB device using
address 2
Sep 27 22:40:04 fezzic kernel: usb 2-2: new full speed USB device using
address 3
Sep 27 22:40:04 fezzic kernel: usb 2-2: configuration #2 chosen from 2
choices
Sep 27 22:40:04 fezzic kernel: drivers/usb/class/usblp.c: usblp0: USB
Bidirectional printer dev 2 if 0 alt 0 proto 2 vid 0x0482 pid 0x0003
Sep 27 22:40:04 fezzic kernel: usbcore: registered new driver usblp
Sep 27 22:40:04 fezzic kernel: drivers/usb/class/usblp.c: v0.13: USB
Printer Device Class driver
Sep 27 22:40:04 fezzic kernel: drivers/usb/class/cdc-acm.c: Ignoring
extra header
Sep 27 22:40:04 fezzic kernel: usbcore: registered new driver cdc_acm
Sep 27 22:40:04 fezzic kernel: drivers/usb/class/cdc-acm.c: v0.23:USB
Abstract Control Model driver for USB modems and ISDN adapters

and trying to start pppd gives me

Sep 27 22:53:08 fezzic pppd[3541]: Failed to open /dev/input/ttyACM0:
Invalid argument

On both systems, lsusb shows the modem and /proc/bus/usb/devices seem
similar, up to a missing driver.

Does anybody have any idea what might be happening here?

Is there any way of forcing the cdc-acm driver to recognise a device as
ACM compatible.