Very annoying problem with udev on Slackware: boot in 5 minutes and over sometimes

Sometimes on boot I read those messages Jan 17 10:06:02 slack64 udevd: worker /devices/pci0000:00/0000:00:08.1/0000:08:00.3/usb3/3-4/3-4.4/3-4.4:1.0/host8/target8:0:0/8:0:0:0/block/sr0 timeout; kill it Jan 17 10:06:02 slack64 udevd: seq 1878 '/devices/pci0000:00/0000:00:08.1/0000:08:00.3/usb3/3-4/3-4.4/3-4.4:1.0/host8/target8:0:0/8:0:0:0/block/sr0' killed Jan 17 10:06:46 slack64 udevd: worker failed while handling '/devices/pci0000:00/0000:00:08.1/0000:08:00.3/usb3/3-4/3-4.4/3-4.4:1.0/host8/target8:0:0/8:0:0:0/block/sr0' The boot is freeze and can stay over 5 minutes without booting. The only solution is this: remove the usb cable of my wifi card (use the 8852bu driver) and reattach it (!) after booting. My question is: how this usb driver can interfere with a block device?sr0 is not a real drive, is a fake driver created by the package vhba-module. The system is Slackware 15.0, the hardware is not important because make the same thing on three different pc. I have tried this method but don't work.