Re: Help: undesired 10 seconds delay in creating USB devices

["Kay Sievers" <kay.sievers@vrfy.org>]

On Thu, Oct 23, 2008 at 18:13, Greg KH <greg@kroah.com> wrote:
> On Thu, Oct 23, 2008 at 01:11:00PM -0300, Gu, Mingkun wrote:

>> [MKGU>] My device driver name is "usbled". Our USB device has
>> VendorID=11b4. After I unplugged the USB cable connecting to this device
>> and kept the device driver "usbled" remaining loaded, I plugged in the
>> USB cable back to the system again. I could see the device information
>> retrieved from /proc/bus/usb/devices immediately but the device name
>> /dev/usbled0 was seen after near 10 seconds.
>
> That sounds like a udev script issue, not a kernel issue, correct?
>
>> > If you run 'udevadm monitor', does it show a 10 second delay?
>>
>> [MKGU>] I don't have the program 'udevadm' on my system.
>
> Do you have the program 'udevmonitor'?  I suggest trying that.

2.6.21.7 (man, these silly numbers, no idea why people want to keep
them :)) should not be affected, as far as I know, but recent kernels
might need a one-line fix to a (broken) udev rule, no to delay
handling of some scsi devices, and wait at the wrong device for a
sysfs file which will never appear. You can try commenting out a rule
in /etc/udev/rules.d/*.rules, which has WAIT_FOR_SYSFS="ioerr_cnt" or
similar.

Kay