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