On Wed, 17 Jun 2009 22:34:40 +0800
Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, 17 Jun 2009, Alek Du wrote:
>
> > It is not simple just let ehci_qh contain the soft part, since the ehci_shadow requires
> > the hardware part to be the first part...
> >
>
> I don't see any problem. Just do this:
>
> union ehci_shadow {
> struct ehci_qh_hw *qh_hw; /* Q_TYPE_QH */
> struct ehci_itd *itd; /* Q_TYPE_ITD */
> struct ehci_sitd *sitd; /* Q_TYPE_SITD */
> struct ehci_fstn *fstn; /* Q_TYPE_FSTN */
> __hc32 *hw_next; /* (all types) */
> void *ptr;
> };
>
> Alan Stern
>
That won't work, for example, some place use ehci_shadow to access qh software part...
Please see the q->qh->usecs, after the above change, the ehci_shadow won't contain the software part...
static unsigned short
periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
{
__hc32 *hw_p = &ehci->periodic [frame];
union ehci_shadow *q = &ehci->pshadow [frame];
unsigned usecs = 0;
while (q->ptr) {
switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
case Q_TYPE_QH:
/* is it in the S-mask? */
if (q->qh->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
usecs += q->qh->usecs;
Alek
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