Bug#677472: [3.1->3.2 regression] Immediate wake on suspend, associated with OHCI on MCP51

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

On Mon, 25 Jun 2012, Octavio Alvarez wrote:

> On Mon, 25 Jun 2012 07:33:11 -0700, Alan Stern <stern@rowland.harvard.edu>
> wrote:
> 
> > What happens if Octavio disables wakeup for that controller before
> > suspending?
> >
> > 	echo disabled >/sys/bus/pci/devices/0000:00:0b.0/power/wakeup
> 
> On kernel 3.2, it lets suspend work again.

It might be worthwhile tracking down the reason for the immediate 
wakeup.  If you build a kernel with CONFIG_USB_DEBUG enabled, what 
shows up in /sys/kernel/debug/usb/ohci/*/registers?  And what shows up 
in /sys/kernel/debug/usb/devices?

Also, what does the "lspci -vv" output show for the controller if you 
run it with superuser permissions?

> For kernel 3.4, I'll break it into two parts: the going asleep and the
> wakening back.
> 
> For the going asleep part, it works just like 3.2. It previously went
> "almost" asleep, but with "echo disabled > wakeup" it suspends correctly.
> 
> For the wakening back part, with both settings the PC locks up requiring a
> mechanical (power supply switch) power cycle to bring the computer back.
> Not even the 5-sec power button cycle helps. I guess this is a different
> bug, so I'll try to troubleshoot it and open a different one.

And yet the PC doesn't lock up if you unbind ohci-hcd before 
suspending?

Maybe you can do a git bisection to find what changed between 3.2 and 
3.4 to cause this behavior.

Alan Stern