Problem with non aligned DMA in usbnet on ARM

You haven't said what HCD you're using.

imx21_hcd  (submitted by me and mainlined in 2.6.34)

In that case, I'd say the HCD must handle misaligned URBs itself so
behaviour is consistent between all implementations on different
platforms.

Here is a pointer to the thread where it was stated that HCD's don't
have to handle this.

http://kerneltrap.org/mailarchive/linux-usb/2009/4/20/5528164