[U-Boot] [PATCH 04/11] usb: ehci: Support interrupt transfers via periodic list

[Marek Vasut]

Dear Simon Glass,

> From: Patrick Georgi <patrick at georgi-clan.de>
> 
> Interrupt transfers aren't meant to be used from the async list
> (the EHCI spec indicates trouble with low/full-speed intr on async).
> 
> Build a periodic list instead, and provide an API to make use of it.
> Then, use that API from the existing interrupt transfer API.
> 
> This provides support for USB keyboards using EHCI.
> 
> Signed-off-by: Patrick Georgi <patrick at georgi-clan.de>
> Signed-off-by: Simon Glass <sjg at chromium.org>
[...]

Looks good in general. Clear up those ToDos please. Also, some while() cycles 
are endless, make use of some timeout please.

Best regards,
Marek Vasut