I tried to use busybox mdev as hotplug handler; and I saw that it doesn't load modules for hot-plugged devices (like usb flash). In /proc/sys/kernel/hotplug there is /sbin/mdev as handler, and module is working - it's successfully loaded by modprobing all modaliases. Kernel - 2.6.35
There is not enough information here to figure out what's going on. Can you install the following shell script, say, /sbin/mdev_debug.sh: #!/bin/sh echo >>/tmp/mdev.trace date >>/tmp/mdev.trace echo "Params: $*" >>/tmp/mdev.trace env | sort >>/tmp/mdev.trace exec /sbin/mdev "$@" instead of /sbin/mdev, then plug usb flash in, wait a few seconds, then attach resulting /tmp/mdev.trace to this bug, along with your mdev.conf
Sorry for long answer waiting, it was more important things for me for that time - but some weeks ago I have time to look on mdev hotplug closer. It really doesn't load modules, and even at first look it haven't code to do this - even in 1.19.0. I made simple wrapper to load/unload modules by hotplug, it was tested on 2.6.21 and 2.6.35 kernels, here it is: #!/bin/sh [ "$ACTION" = add ] && [ "$MODALIAS" != "" ] && modprobe $MODALIAS [ "$ACTION" = remove ] && [ "$MODALIAS" != "" ] && modprobe -r $MODALIAS /sbin/mdev $@ It works good, but IMHO it'll be better if modules will be loaded by mdev itself. Here is mdev.trace: # cat /tmp/mdev.trace Sat Aug 27 11:32:36 EEST 2011 Params: usb ACTION=add BUSNUM=003 DEVICE=/proc/bus/usb/003/002 DEVNAME=bus/usb/003/002 DEVNUM=002 DEVPATH=/devices/pci0000:00/0000:00:02.2/usb3/3-1 DEVTYPE=usb_device HOME=/ MAJOR=189 MINOR=257 PATH=/sbin:/bin:/usr/sbin:/usr/bin PHYSDEVBUS=usb PRODUCT=4e8/1623/100 PWD=/ SEQNUM=1022 SUBSYSTEM=usb TYPE=0/0/0 Sat Aug 27 11:32:36 EEST 2011 Params: usb ACTION=add DEVICE=/proc/bus/usb/003/002 DEVPATH=/devices/pci0000:00/0000:00:02.2/usb3/3-1/3-1:1.0 DEVTYPE=usb_interface HOME=/ INTERFACE=8/6/80 MODALIAS=usb:v04E8p1623d0100dc00dsc00dp00ic08isc06ip50 PATH=/sbin:/bin:/usr/sbin:/usr/bin PHYSDEVBUS=usb PRODUCT=4e8/1623/100 PWD=/ SEQNUM=1023 SUBSYSTEM=usb TYPE=0/0/0 Sat Aug 27 11:33:17 EEST 2011 Params: usb ACTION=add BUSNUM=001 DEVICE=/proc/bus/usb/001/002 DEVNAME=bus/usb/001/002 DEVNUM=002 DEVPATH=/devices/pci0000:00/0000:00:02.0/usb1/1-2 DEVTYPE=usb_device HOME=/ MAJOR=189 MINOR=1 PATH=/sbin:/bin:/usr/sbin:/usr/bin PHYSDEVBUS=usb PRODUCT=d9f/2/0 PWD=/ SEQNUM=1024 SUBSYSTEM=usb TYPE=0/0/0 Sat Aug 27 11:33:17 EEST 2011 Params: usb ACTION=add DEVICE=/proc/bus/usb/001/002 DEVPATH=/devices/pci0000:00/0000:00:02.0/usb1/1-2/1-2:1.0 DEVTYPE=usb_interface HOME=/ INTERFACE=3/0/0 MODALIAS=usb:v0D9Fp0002d0000dc00dsc00dp00ic03isc00ip00 PATH=/sbin:/bin:/usr/sbin:/usr/bin PHYSDEVBUS=usb PRODUCT=d9f/2/0 PWD=/ SEQNUM=1025 SUBSYSTEM=usb TYPE=0/0/0 Sat Aug 27 11:33:24 EEST 2011 Params: usb Sat Aug 27 11:33:24 EEST 2011 Params: usb ACTION=remove DEVICE=/proc/bus/usb/003/002 DEVPATH=/devices/pci0000:00/0000:00:02.2/usb3/3-1/3-1:1.0 DEVTYPE=usb_interface HOME=/ INTERFACE=8/6/80 MODALIAS=usb:v04E8p1623d0100dc00dsc00dp00ic08isc06ip50 PATH=/sbin:/bin:/usr/sbin:/usr/bin PHYSDEVBUS=usb PRODUCT=4e8/1623/100 PWD=/ SEQNUM=1026 SUBSYSTEM=usb TYPE=0/0/0 ACTION=remove BUSNUM=003 DEVICE=/proc/bus/usb/003/002 DEVNAME=bus/usb/003/002 DEVNUM=002 DEVPATH=/devices/pci0000:00/0000:00:02.2/usb3/3-1 DEVTYPE=usb_device HOME=/ MAJOR=189 MINOR=257 PATH=/sbin:/bin:/usr/sbin:/usr/bin PHYSDEVBUS=usb PRODUCT=4e8/1623/100 PWD=/ SEQNUM=1027 SUBSYSTEM=usb TYPE=0/0/0