Re: How is /dev/bus/usb created - /dev/bus/usb lost during system

[Martin Pitt <martin.pitt@ubuntu.com>]

Hello Petr,

Petr Kubánek [2010-03-18  2:24 +0100]:
> I lost /dev/bus/usb during remote system upgrade (Ubuntu 9.04 -> 9.10)
> on Watcher telescope control computer (@Boyden observatory, South
> Africa).
> 
> I do not see /dev/bus/usb, and lsusb does not show anything. It worked
> before, USB devices are present in dmesg, so I think USB subsystem is
> working properly.
> 
> To debug this it will help me to know how udev creates and
> populates /dev/bus/usb - which rule(s) does this, how to debug what
> might be wrong.

Those are just created by udev, there is no particular rule for it
(it's using the kernel default name).

$ udevadm test /bus/usb/devices/1-8
[...]
udev_rules_apply_to_event: LINK 'char/189:2' /lib/udev/rules.d/50-udev-default.rules:4
udev_rules_apply_to_event: MODE 0664 /lib/udev/rules.d/50-udev-default.rules:62
udev_rules_apply_to_event: RUN 'socket:@/org/freedesktop/hal/udev_event' /lib/udev/rules.d/90-hal.rules:2
udev_event_execute_rules: no node name set, will use kernel supplied name 'bus/usb/001/003'
[...]
udevadm_test: DEVPATH=/devices/pci0000:00/0000:00:1d.7/usb1/1-8
udevadm_test: DEVNAME=/dev/bus/usb/001/003
[...]

My best guess is that you are running a custom kernel which perhaps
has CONFIG_SYSFS_DEPRECATED_V2 set, or something similar? What does
"uname -a" say?

Martin

-- 
Martin Pitt                        | http://www.piware.de
Ubuntu Developer (www.ubuntu.com)  | Debian Developer  (www.debian.org)