On Mon, 29 Jun 2015, Peter Chen wrote:

> Just like Steve pointed, it should be a ZLT problem, do you have
> below patch in your tree, and the host may not send zlt, but you
> may queue an zero-length request, the f_hid does not set req->zero
> flag either.
> 
> commit 953c66469735aed8d2ada639a72b150f01dae605
> Author: Abbas Raza <abbas_r...@mentor.com>
> Date:   Thu Jul 17 19:34:31 2014 +0800
> 
>     usb: chipidea: udc: Disable auto ZLP generation on ep0
> 
> 
> If it still has problem, send me apps if possible (with needed kernel
> patches).

Note that a UDC should _never_ queue an extra zero-length packet for an
OUT transfer, no matter how req->zero is set.  In other words,
req->zero is supposed to affect only IN transfers.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to