g_vfs_done() error=5 USB disk on raspberrypi. Decrease the speed of USB

[Aurelien Martin]

Dear all,

My raspberry-pi is crashing in g_vfs_done error 5 () when I'm trying to
copy data from the rpi (with dd) to my USB drive on UFS2
I can notice a high %system load ~100% on the rpi before the crash

Apparently people succeed to "fix it" by decreasing the speed of the USB
bus with sysctl hw.usb.ehci.no_hs = 1

But in my case I cannot set this sysctl. And I didn't succeed to fix it
with camcontrol

Can you guide me on my investigation to decrease the speed of USB ?

Thanks for your work.

Cheers,Aurelien

Log
--

# uname -a
FreeBSD rpi-aurelien 11.0-CURRENT FreeBSD 11.0-CURRENT #0 r271779: Fri Sep
19 01:18:53 UTC 2014
root at grind.freebsd.org:/usr/obj/arm.armv6/usr/src/sys/RPI-B
arm

# sysctl hw.usb.ehci
sysctl: unknown oid 'hw.usb.ehci': No such file or directory

# usbconfig -d ugen0.5 show_ifdrv
ugen0.5: <USB to ATAATAPI bridge JMicron> at usbus0, cfg=0 md=HOST spd=HIGH
(480Mbps) pwr=ON (2mA)
ugen0.5.0: umass0: <Storage>

 # camcontrol
devlist

<WDC WD10 EADS-00L5B1 01.0>        at scbus0 target 0 lun 0 (da0)

# kldstat -v | grep ehci
                47 ehci/usbus