USB: device at 12 MBit instead of 480 MBit

[^rooker]

[PROBLEM]
I connected a Maxtor OneTouch 4 to my USB ports and it was incredibly slow.
doing a

Code: Select all

cat /proc/bus/usb/devices

revealed that it was connected at 12 MBit/s (full speed) instead of 480 MBit/s (high speed):

T: Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 5 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=0d49 ProdID=7310 Rev= 1.25
S: Manufacturer=Maxtor
S: Product=OneTouch
S: SerialNumber=xxxxxxxx
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr= 2mA
I: If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
E: Ad=81(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms

The host hub however claimed to be running at 480 MBit/s.

[SOLUTION]
I had to remove the USB kernel modules (uhci-hcd (slow) and ehci-hcd (fast)), reconnect the drive and then reload the fast USB driver (ehci-hcd):

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rmmod uhci-hcd
rmmod ehci-hcd
# unplug & re-plug the harddisk
modprobe ehci-hcd

Now it was running at high speed:

T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 2 Spd=480 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=0d49 ProdID=7310 Rev= 1.25
S: Manufacturer=Maxtor
S: Product=OneTouch
S: SerialNumber=xxxxxxxx
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr= 2mA
I: If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms

Useful links:
http://www.linux-usb.org/
http://en.wikipedia.org/wiki/Usb
http://www.linux-usb.org/USB-guide/c607.html