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

[Stephen Warren]

On 08/18/2015 05:55 AM, Guillaume Gardet wrote:
> 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)?

Yes, that's unfortunately expected at present.