[Debian Kirkwood kernel 3.10.4] udev does not enumerate USB devices in rootfs pre-mount?

It seems something has changed in kernel 3.10.x. I'm having problem with mounting rootfs in kernel 3.10.4. Comparing the dmesg log for kernel 3.9.11 and 3.10.4, I noticed that udev did not seem to enumerate the USB devices during loading rootfs (in initrd pre-mount). That caused the classic /dev/root not found problem. I've confirmed this was the problem by looking at /dev while inside initramfs prompt, and there were no sdx devices there.

Below are the 2 log files excerpts. The first one is kernel 3.10.4, the second one is kernel 3.9.11. Anybody know how to solve this? or seen this problem?

Thanks!

dmesg (kernel 3.10.4 not working)

[   22.313191] udevd[51]: starting version 175
[   22.380897] mv643xx_eth: MV-643xx 10/100/1000 ethernet driver version 1.4
[   22.482274] libphy: orion_mdio_bus: probed
[   22.502334] SCSI subsystem initialized
[   22.513366] mv643xx_eth_port mv643xx_eth_port.0 eth0: port 0 with MAC address xx:xx:xx:xx:xx:xx
[   22.575220] sata_mv sata_mv.0: cannot get optional clkdev
[   22.580706] sata_mv sata_mv.0: slots 32 ports 1
[   22.630331] scsi0 : sata_mv
[   22.641982] ata1: SATA max UDMA/133 irq 21
[   23.002537] ata1: SATA link down (SStatus 0 SControl F300)
Begin: Loading essential drivers ... done.
Begin: Running /scripts/init-premount ... done.
Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done.
Begin: Waiting for root file system ... done.
Gave up waiting for root device.  Common problems:
 - Boot args (cat /proc/cmdline)
   - Check rootdelay= (did the system wait long enough?)
   - Check root= (did the system wait for the right device?)
 - Missing modules (cat /proc/modules; ls /dev)
ALERT!  /dev/disk/by-label/rootfs does not exist.  Dropping to a shell!
modprobe: module i8042 not found in modules.dep
[   43.329907] usbcore: registered new interface driver usbfs
[   43.336605] usbcore: registered new interface driver hub
[   43.343080] usbcore: registered new device driver usb
[   43.351562] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[   43.366490] uhci_hcd: USB Universal Host Controller Interface driver
[   43.382336] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[   43.403118] hidraw: raw HID events driver (C) Jiri Kosina
[   43.412903] usbcore: registered new interface driver usbhid
[   43.418510] usbhid: USB HID core driver

dmesg (kernel 3.9.11 working)

Loading, please wait...
[    4.939941] udevd[51]: starting version 175
[    5.036936] mv643xx_eth: MV-643xx 10/100/1000 ethernet driver version 1.4
[    5.084581] usbcore: registered new interface driver usbfs
[    5.103126] libphy: mv643xx_eth smi: probed
[    5.126159] usbcore: registered new interface driver hub
[    5.139032] SCSI subsystem initialized
[    5.146340] mv643xx_eth_port mv643xx_eth_port.0 eth0: port 0 with MAC address xx:xx:xx:xx:xx:xx
[    5.179511] usbcore: registered new device driver usb
[    5.186534] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[    5.220214] sata_mv sata_mv.0: cannot get optional clkdev
[    5.225687] sata_mv sata_mv.0: slots 32 ports 1
[    5.278290] scsi0 : sata_mv
[    5.281388] ata1: SATA max UDMA/133 irq 21
[    5.307073] orion-ehci orion-ehci.0: Marvell Orion EHCI
[    5.319713] orion-ehci orion-ehci.0: new USB bus registered, assigned bus number 1
[    5.327500] orion-ehci orion-ehci.0: irq 19, io mem 0xf1050000
[    5.349293] orion-ehci orion-ehci.0: USB 2.0 started, EHCI 1.00
[    5.355324] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[    5.362172] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    5.369445] usb usb1: Product: Marvell Orion EHCI
[    5.374172] usb usb1: Manufacturer: Linux 3.9.11-kirkwood-tld-2 ehci_hcd