Re: [RFC PATCH 4/6] USB: ehci-omap: Suspend the controller duringbus suspend

From: Alan Stern
Date: Thu Jun 20 2013 - 13:33:13 EST

On Thu, 20 Jun 2013, Roger Quadros wrote:

> > runtime_resume(dev)
> > {
> > ...
> >
> > if (omap->flags & OMAP_EHCI_IRQ_PENDING) {
> > process_pending_irqs(omap);
> OK, thanks.
> But I'm not sure if the generic ehci_irq handler is able to
> run in a process context. Maybe if we replace spin_lock(&ehci->lock);
> with spin_lock_irqsave() there, it will work.
> Alan is this a doable option?

ehci_irq() will work okay in process context, provided the caller
disables interrupts.

But maybe none of this will be needed after Roger redesigns the
controller suspend to work at the right time. Or if it is, we could
adopt a simpler alternative: the controller's resume routine could
always call usb_hcd_resume_root_hub(). After all, about the only
reason for doing a runtime resume of the controller is because the root
hub needs to do something.

Alan Stern

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