[U-Boot] usbkbd input double echoed

Hi all,

I've enabled USB keyboard for cm_fx6 using these three defines:

#define CONFIG_USB_KEYBOARD #define CONFIG_SYS_USB_EVENT_POLL #define CONFIG_SYS_STDIO_DEREGISTER

I am able to probe it with `usb start`, and set it as input using `setenv stdin usbkbd`.

It works, save for one problem: all key presses are echoed twice. The double echo happens both on serial and vga stdout. It is not dependant on the keyboard (tried different ones). Output from commands looks normal. Switching to CONFIG_SYS_USB_EVENT_POLL_VIA_CONTROL_EP did not help. Shell still understands each key press as one key press, so even though "pprriinntteennvv" is displayed, the shell still sees "printenv".

Any idea what the cause may be?