On Mon, 25 May 2009, David wrote:
> David wrote:
> > Alan Stern wrote:
> >
> >> Okay, here's a patch for you to try. It refreshes the toggle setting
> >> in a linked but otherwise idle QH when a new URB is queued.
> >>
> >> Alan Stern
> >>
> >>
> >> Index: usb-2.6/drivers/usb/host/ehci-q.c
> >> ===================================================================
> >> --- usb-2.6.orig/drivers/usb/host/ehci-q.c
> >> +++ usb-2.6/drivers/usb/host/ehci-q.c
> >> @@ -88,7 +88,7 @@ static inline void
> >> qh_update (struct ehci_hcd *ehci, struct ehci_qh *qh, struct ehci_qtd
> >> *qtd)
> >> {
> >> /* writes to an active overlay are unsafe */
> >> - BUG_ON(qh->qh_state != QH_STATE_IDLE);
> >> + BUG_ON(qh->qh_state != QH_STATE_IDLE && !list_empty(&qh->qtd_list));
> >>
> >> qh->hw_qtd_next = QTD_NEXT(ehci, qtd->qtd_dma);
> >> qh->hw_alt_next = EHCI_LIST_END(ehci);
> >> @@ -971,7 +971,13 @@ static struct ehci_qh *qh_append_tds (
> >> /* can't sleep here, we have ehci->lock... */
> >> qh = qh_make (ehci, urb, GFP_ATOMIC);
> >> *ptr = qh;
> >> + } else if (list_empty(&qh->qtd_list)) {
> >> + /* There might have been a Clear-Halt while the QH
> >> + * was linked but empty.
> >> + */
> >> + qh_refresh(ehci, qh);
> >> }
> >> +
> >> if (likely (qh != NULL)) {
> >> struct ehci_qtd *qtd;
> >>
> >>
> >>
> >>
> > No luck I'm afraid (although there now appear to be 2 timeouts, not
> > one). I'm going to follow up on the laptop and get a USB log.
> >
> USB log post-patch attached. Thanks for all the effort so far!
Yes, the log shows two timeouts. Maybe I misunderstood something and
the patch only made the situation worse!
We may have to try a debugging patch to find out what's really
happening here. I'll get back to you on that...
Alan Stern
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