On Tue, 18 Jun 2013, Manjunath Goudar wrote:
> After Alan explanation I am writing below code end of ohci_suspend()
> routine.is it correct Alan.
>
> if (do_wakeup && HCD_WAKEUP_PENDING(hcd)) {
> ohci_resume(hcd, false);
> rc = -EBUSY;
> }
I'm glad you asked, because there is an important part I forgot about.
Just before the code above, it is also necessary to add:
synchronize_irq(hcd->irq);
The reason is because a wakeup interrupt might race with the suspend
call. If the suspend finishes first, we need to wait until the
interrupt has been handled before checking whether there is a pending
wakeup. That's what synchronize_irq() does; it waits until all the
outstanding interrupt requests have been handled.
(Also, as Sachin pointed out, you have to return rc instead of 0.)
Alan Stern
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