Hi Wolfgang/Sergei,
2010/6/25 Sergei Shtylyov sshtylyov@ru.mvista.com:
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 "next" pointers in the QH transfer overlay...
Signed-off-by: Sergei Shtylyov sshtylyov@mvista.com
Acked-by: Remy Bohmer linux@bohmer.net
Wolfgang, can you please pull this patch in the v2010.06 release?
Kind regards,
Remy
This is quite serious error, so would be good to have the patch in v2010.06...
drivers/usb/host/ehci-hcd.c | 4 +--- 1 file changed, 1 insertion(+), 3 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; }
@@ -349,8 +349,6 @@ ehci_submit_async(struct usb_device *dev (dev->portnr << 23) | (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;