Re: 3.12: ethernet controller missing after resuming from suspend to RAM

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Saturday, February 08, 2014 10:34:23 PM Peter Wu wrote:
> On Saturday 08 February 2014 16:01:36 Rafael J. Wysocki wrote:
> > It looks like we fail to resume the device, then, for some reason.
> > 
> > That may be a PCIe link issue or something similar.
> > 
> > Is this a regression for you?  If so, what's the last kernel that didn't
> > have this problem?  Does 3.13.y (as released by Greg, without and distro
> > "improvements") have it too?
> 
> It was a regression from 3.11.x to 3.12 (and it is still broken with 3.13).
> Due to some mistakes from my side, I have tested more configs:
> 
> (based on Arch Linux 3.13.1 x86_64 config)
> (a) 3.13.2 with CONFIG_HOTPLUG_PCI=y, but CONFIG_HOTPLUG_PCI_ACPI=n works.
> (b) 3.13.2 with CONFIG_HOTPLUG_PCI=y and CONFIG_HOTPLUG_PCI_ACPI=y is broken.
> (c) 3.13.2 with CONFIG_HOTPLUG_PCI=n still works.
> (my stripped config)
> (d) 3.13.2 with CONFIG_HOTPLUG_PCI=y, but CONFIG_HOTPLUG_PCI_ACPI=n works.
> 
> With CONFIG_HOTPLUG_PCI_ACPI=y, the only difference in dmesg is:
> 
> (during boot)
> acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
> (after resume)
> iwlwifi 0000:05:00.0: no hotplug settings from platform
> xhci_hcd 0000:02:00.0: no hotplug settings from platform
>  (here, NetworkManager complains that a device has gone)
> iwlwifi 0000:05:00.0: no hotplug settings from platform
> 
> Of course, with config (b), the ethernet adapter vanishes while it is still
> present with configs (a), (c) and (d).
> 
> Time to do a bisect?

That most likely would single out one of the ACPIPHP commits without giving us
much clue about what's going on.

I fail to see what the connection between those changes and system resume is,
however.

Please replace all pr_debug() calls in hotplug_notify() with pr_info() and
see if you get any events from there.

Thanks!

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.