smsc95xx: download ok, upload hangs

Hi,

I am experiencing ethernet issue with a pandaboard A3 (OMAP4430 rev 2.2) featuring smsc LAN9514-JZX
usbnet chipset.
My panda runs android-4.0.4 with linux kernel 3.0.8 (the latest from omapzoom).

Receiving ethernet frames work fine, but transmitting them does not. The driver/chip seems stuck.
Moving the USB mouse (or USB keyboard key pressed) unlocks this behavior and transmission gets resumed for
a second or two. Then ethernet transmission gets stuck again.

Recently, I cherry-picked dozen of usbnet and smsc95xx patches, and managed to get a watchdog barking (see
test 21 below).

Unfortunately I have no JTAG probe, so I am limited to driver tweaks and tryouts...
Here are the tests I have performed so far, along with a todo list:

FAILED means that the issue came up.
PASSED means that the issue has not come up.
DONE, NOT DONE, ONGOING are more related to a todo list than a test report.

1. check with constant cpu load (stress -c 2) - FAILED
2. check if problem occurs on older releases (non ICS) - NOT DONE
3. try CONFIG_PL310_ERRATA_769419 patch in cpuidle - FAILED
4. check without USB hub connected - FAILED
5. check with usbcore.autosuspend=600 added to cmdline - FAILED
6. patch ehci-omap.c to verify clock frequency - NOT DONE
7. check with CPU1 offlined - FAILED
8. check ethtool on android - FAILED
Cannot get register dump: Operation not supported on transport endpoint
9. check without USB_EHCI_TT_NEWSCHED - FAILED