[U-Boot] [RFC PATCH] usb: kbd: add transfer error interrupt handling

[Stephen Warren <swarren@wwwdotorg.org>]

On 04/10/2015 09:07 PM, Stephen Warren wrote:
> If the USB transfer fails or otherwise returns no data, don't process the
> (non-existent) reponse data and generate keypresses from it. Doing so
> makes each successful transaction appear to be a new keypress, which
> results in ridiculously fast key repeat rates.
> 
> FIXME: This breaks USB keyboard on at least NVIDIA Tegra Seaboard, hence
> why this is an RFC.

I've tracked down the issue here, and it looks like I can replace this
patch with a patch to DWC2. So, ignore this patch and I'll post the DWC2
patch soon; it's working now but I need to add a timeout to a loop and
do some more testing.

> I wonder if submit_int_msg() is expected to keep executing until a
> successful transfer is made? That would likely explain why the existing
> lack of error handling has no negative effect on non-DWC2 platforms.