[linux-pm] ehci_hcd related S3 lockup on ASUS laptops, again

[Alan Stern]

On Wed, 18 Apr 2012, Andrey Rahmatullin wrote:

> > Wow.  Okay, I have boiled this down to a single patch.  You should 
> > try this both with and without unbinding ehci-hcd, and post the dmesg 
> > log output that it generates in the two cases.
> 
> Unbound:
> 
> pci 0000:00:1d.0: wake-up capability enabled by ACPI
> pci 0000:00:1d.0: Refused to change power state, currently in D0
> pci 0000:00:1d.0: cur 5 target 3 error 0
> pci 0000:00:1a.0: wake-up capability enabled by ACPI
> pci 0000:00:1a.0: Refused to change power state, currently in D0
> pci 0000:00:1a.0: cur 5 target 3 error 0
> 
> Bound:
> 
> ehci_hcd 0000:00:1d.0: wake-up capability enabled by ACPI
> ehci_hcd 0000:00:1d.0: Refused to change power state, currently in D0
> ehci_hcd 0000:00:1d.0: cur 5 target 3 error 0
> ehci_hcd 0000:00:1a.0: wake-up capability enabled by ACPI
> ehci_hcd 0000:00:1a.0: Refused to change power state, currently in D0
> ehci_hcd 0000:00:1a.0: cur 5 target 3 error 0

Very good.  The two behaviors are the same.

Now if you modify the patch by removing the change to hcd-pci.c, which 
will leave the EHCI code exactly the same as in the vanilla kernel, and 
set the pm_test value to "platform", what does the dmesg log show in 
the two cases?

Steven reported that the power state does get set to D3hot; he did not
get the "Refused to change power state" lines.

I have a strong feeling that your computer crashes during suspend 
whenever the EHCI controllers are in a low-power state.  We'll see.

Alan Stern