Re: ehci_hcd related S3 lockup on ASUS laptops, again

[Alan Stern <stern@rowland.harvard.edu>]

On Thu, 12 Apr 2012, Steven Rostedt wrote:

> > Anyway, this shows that the EHCI controllers are being set to the same 
> > power state with the same wakeup settings in both cases.  And yet one 
> > hangs the computer while the other doesn't.
> > 
> > Here's another rather drastic test you can do.  In 
> > drivers/usb/host/ehci-pci.c:ehci_pci_suspend(), call ehci_reset(ehci) 
> > just before the final return statement.  That should leave the hardware 
> > in exactly the same state as if ehci-hcd had been unbound.
> 
> Want me to remove previous updates before doing so? I can keep the
> dev_log, but what about the other change you asked about.

Keep them.

Asumming you get the same result as Andrey, that the computer still
hangs even with the ehci_reset() call, there's one more thing for the 
two of you to try.

I noted before that with ehci-hcd bound, it would call 
pci_disable_device.  But with the driver unbound, the PCI core calls 
pci_disable_enabled_device instead.

So let's have the driver do the same thing.  At the end of
drivers/usb/core/hcd-pci.c:suspend_common, change pci_disable_device to
pci_disable_enabled_device.  You'll also have to EXPORT that routine;
it's defined in drivers/pci/pci.c.

Do this with the ehci_reset added and all the other changes present as 
well.  Then there should be no difference at all between the two 
scenarios.

Alan Stern