On Wed, 17 Jun 2009, Alek Du wrote:
> 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;
So change this line to
usecs += q->qh_hw->sw->usecs;
Isn't that more or less what your ealier patch did anyway? Although it
would be better to change the code as follows:
{
__hc32 *hw_p = &ehci->periodic [frame];
union ehci_shadow *q = &ehci->pshadow [frame];
unsigned usecs = 0;
struct ehci_qh *qh;
while (q->ptr) {
switch (hc32_to_cpu(ehci, Q_NEXT_TYPE(ehci, *hw_p))) {
case Q_TYPE_QH:
qh = q->qh_hw->sw;
/* is it in the S-mask? */
if (q->qh_hw->hw_info2 & cpu_to_hc32(ehci, 1 << uframe))
usecs += qh->usecs;
/* ... or C-mask? */
if (q->qh_hw->hw_info2 & cpu_to_hc32(ehci,
1 << (8 + uframe)))
usecs += qh->c_usecs;
hw_p = &q->qh_hw->hw_next;
q = &qh->qh_next;
break;
Alan Stern
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