Some race during coldplug prevents USB controllers modules from being loaded, they can't find some usbcore symbols at loading time.

https://bugs.launchpad.net/ubuntu/+source/module-init-tools/+bug/24238 http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=333052

The suggested patches have been applied upstream, so we already have them in the distro. The loop checking module loading status in /proc/modules should have been enough, need to investigate more.

Debian lowered the bug importance not to block their final release, and the bug was eventually marked as fixed later, without valuable explanation.

• /usr/src/linux/kernel/module.c
• module-init-tools-3.3-pre11/libmodprobe.c

Trying rmmod ehci_hcd; rmmod uhci_hcd; umount /proc/bus/usb; rmmod usbcore; udevtrigger; grep usb /proc/modules to reproduce isn't enough, the bug probably appears only when the system is overloaded.

Linux agpgart interface v0.102 (c) Dave Jones
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
iTCO_vendor_support: vendor-support=0
usbcore: registered new device driver usb
agpgart: Detected an Intel 915GM Chipset.
agpgart: Detected 7932K stolen memory.
agpgart: AGP aperture is 256M @ 0xc0000000
iTCO_wdt: Intel TCO WatchDog Timer Driver v1.01 (21-Jan-2007)
iTCO_wdt: Found a ICH6-M TCO device (Version=2, TCOBASE=0x1060)
iTCO_wdt: initialized. heartbeat=30 sec (nowayout=1)
uhci_hcd: Unknown symbol usb_hcd_pci_suspend
uhci_hcd: Unknown symbol usb_hcd_resume_root_hub
uhci_hcd: Unknown symbol usb_hcd_pci_probe
uhci_hcd: Unknown symbol usb_disabled
uhci_hcd: Unknown symbol usb_calc_bus_time
uhci_hcd: Unknown symbol usb_hcd_pci_resume
uhci_hcd: Unknown symbol usb_hcd_giveback_urb
uhci_hcd: Unknown symbol usb_hcd_poll_rh_status
uhci_hcd: Unknown symbol usb_hcd_pci_remove
uhci_hcd: Unknown symbol usb_root_hub_lost_power
ACPI: PCI Interrupt 0000:00:1f.3[B] -> GSI 17 (level, low) -> IRQ 17
USB Universal Host Controller Interface driver v3.0
ACPI: PCI Interrupt 0000:00:1d.0[A] -> GSI 16 (level, low) -> IRQ 16
PCI: Setting latency timer of device 0000:00:1d.0 to 64
uhci_hcd 0000:00:1d.0: UHCI Host Controller
uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus number 1
uhci_hcd 0000:00:1d.0: irq 16, io base 0x0000bf80
usb usb1: configuration [#1 http://qa.mandriva.com/show_bug.cgi?id=1] chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
ACPI: PCI Interrupt 0000:00:1d.1[B] -> GSI 17 (level, low) -> IRQ 17
PCI: Setting latency timer of device 0000:00:1d.1 to 64
uhci_hcd 0000:00:1d.1: UHCI Host Controller
uhci_hcd 0000:00:1d.1: new USB bus registered, assigned bus number 2
uhci_hcd 0000:00:1d.1: irq 17, io base 0x0000bf60
usb usb2: configuration [#1 http://qa.mandriva.com/show_bug.cgi?id=1] chosen from 1 choice
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 2 ports detected
ACPI: PCI Interrupt 0000:00:1d.2[C] -> GSI 18 (level, low) -> IRQ 18
PCI: Setting latency timer of device 0000:00:1d.2 to 64
uhci_hcd 0000:00:1d.2: UHCI Host Controller
uhci_hcd 0000:00:1d.2: new USB bus registered, assigned bus number 3
uhci_hcd 0000:00:1d.2: irq 18, io base 0x0000bf40
usb usb3: configuration [#1 http://qa.mandriva.com/show_bug.cgi?id=1] chosen from 1 choice
hub 3-0:1.0: USB hub found
hub 3-0:1.0: 2 ports detected
intel_rng: FWH not detected

$ grep usb_hcd_pci_suspend /lib/modules/2.6.22-4mdv/modules.symbols 
alias symbol:usb_hcd_pci_suspend usbcore