[U-Boot] USB keyboard does not work on DWC2 controller (on Raspberry Pi B)

[Guillaume Gardet <guillaume.gardet@free.fr>]

Hi Stephen,

I want to add USB keyboard support to raspberry pi but I get the following error when I do 'usb start' with a keyboard plugged-in:
     unable to get device descriptor (error=-22)

Ethernet chip and mass storage devices are found.

I found this thread from February: http://lists.denx.de/pipermail/u-boot/2015-February/206593.html
which says:
**********
     This error is because the keyboard driver uses interrupt transfers, and
     these aren't implemented in DWC2
**********

But in  April, you added a patch series including "usb: dwc2: implement interrupt transfers".
But there is also a note:
**********
     With all these commits applied, both my USB keyboards (one LS Lenovo and
     one FS Dell) work correctly when there is no USB hub between the SoC and
     the keyboard; We still need split transactions to be implemented for hubs
     to work.
**********

So, I guess this is expected that USB keyboard does not work on DWC2 / RPi B since it uses a USB hub (SMSC LAN9512)?


Guillaume