Re: asynchronous ugen(4) bulk transfers

[Nick Hudson <skrll%netbsd.org@localhost>]

On 04/04/16 08:45, Nick Hudson wrote:
> On 04/04/16 05:25, Brian Buhrow wrote:
> >     hello.  I did a lot of work on this under NetBSD-5  to allow the
> > libimobiledevice tools to work with iOS based Apple devices.  I have 
> > some
> > simple patches for libusb1 and a re-working of the ugen(4) driver to
> > address the issues you note below.  My plan is to port these fixes to
> > -current, but I hadn't finished that process yet.  My changes make the
> > libimobiledevice tools work reliably with Apple products, modulo a 
> > bug in
> > the ehci(4) and ohci(4) drivers that preclude the USB stack from sending
> > zero-length packets.
>
> Not that I think ehci(4) has a problem in HEAD

Does this diff help ehci+zlp for you? Thanks to Colin Granville for the 
hint.

Nick

Index: sys/dev/usb/ehci.c
===================================================================
RCS file: /cvsroot/src/sys/dev/usb/ehci.c,v
retrieving revision 1.248
diff -u -p -r1.248 ehci.c
--- sys/dev/usb/ehci.c	13 Mar 2016 07:01:43 -0000	1.248
+++ sys/dev/usb/ehci.c	5 Apr 2016 06:57:13 -0000
@@ -2975,7 +2975,7 @@ ehci_alloc_sqtd_chain(struct ehci_pipe *
 
 		/* adjust the toggle based on the number of packets in this
 		   qtd */
-		if (((curlen + mps - 1) / mps) & 1) {
+		if (curlen == 0 || (((curlen + mps - 1) / mps) & 1)) {
 			tog ^= 1;
 			qtdstatus ^= EHCI_QTD_TOGGLE_MASK;
 		}