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 - To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
