[U-Boot] [PATCH v2] EHCI: zero out QH transfer overlay in ehci_submit_async()

[Sergei Shtylyov]

ehci_submit_async() doesn't really zero out the QH transfer overlay (as the EHCI
specification suggests) which leads to the controller seeing the "token" field
as the previous call has left it, i.e.:
- if a timeout occured on the previous call (Active bit left as 1), controller
  incorrectly tries to complete a previous transaction on a newly programmed
  endpoint;
- if a halt occured on the previous call (Halted bit set to 1), controller just
  ignores the newly programmed TD(s) and the function then keeps returning error
  ad infinitum.

This turned out to be caused by the wrong orger of the arguments to the memset()
call in ehci_alloc(), so the allocated TDs weren't cleared either.

While at it, stop needlessly initializing the alternate next TD pointer in the
QH transfer overlay...

Signed-off-by: Sergei Shtylyov <sshtylyov at ru.mvista.com>

---
Initialization of 'qh->qh_overlay.qt_next' turned out to be needed by the error
cleanup code (seemingly useless, in its turn).

This is quite serious bug, so would be good to have the patch in v2010.06...

 drivers/usb/host/ehci-hcd.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Index: u-boot/drivers/usb/host/ehci-hcd.c
===================================================================
--- u-boot.orig/drivers/usb/host/ehci-hcd.c
+++ u-boot/drivers/usb/host/ehci-hcd.c
@@ -275,7 +275,7 @@ static void *ehci_alloc(size_t sz, size_
 		return NULL;
 	}
 
-	memset(p, sz, 0);
+	memset(p, 0, sz);
 	return p;
 }
 
@@ -350,7 +350,6 @@ ehci_submit_async(struct usb_device *dev
 	    (dev->parent->devnum << 16) | (0 << 8) | (0 << 0);
 	qh->qh_endpt2 = cpu_to_hc32(endpt);
 	qh->qh_overlay.qt_next = cpu_to_hc32(QT_NEXT_TERMINATE);
-	qh->qh_overlay.qt_altnext = cpu_to_hc32(QT_NEXT_TERMINATE);
 
 	td = NULL;
 	tdp = &qh->qh_overlay.qt_next;