OMAP34xx EHCI bulk OUT CRC16 complementing

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USB EHCI/OHCI experts

On omap-git v2.6.25-rc2, TI OMAP34xx EHCI controller, we are seeing a strange behavior on a bulk OUT 512 byte transfer.

We can see through the CATC that the 512 byte goes out successfully but there are many Turnaround/Timeout Errors and retries before the packet goes out successfully. 
The retries could range from 0 to 10 or more.

The error packets have 'CRC16 complemented' as per Section 8.6.4 page 234-235 that says for probably a data under-run condition:
"An error for high-speed must be forced by taking the currently calculated CRC and complementing it before transmitting it."

We have confirmed that our Memory (SDRAM) access have a much higher bandwidth available "not" to cause data under-run condition.

Where in EHCI stack should I debug for this issue? 

I am checking: qh_append_tds()
Not sure how this "Dummy" qtd is implemented. Anything to do with this? 

Is there a way to slow-down the OUT transfers on EHCI if that helps in debugging? 

Regards
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