Re: [Bug 213873] New: Hotplug ethernet cable to runtime suspended Realtek NIC doesn't raise PCIe PME IRQ on Intel ADL

[Kai-Heng Feng <kai.heng.feng@canonical.com>]

On Tue, Jul 27, 2021 at 11:55 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> On Tue, Jul 27, 2021 at 06:10:13AM +0000, bugzilla-daemon@bugzilla.kernel.org wrote:
> > https://bugzilla.kernel.org/show_bug.cgi?id=213873
> >
> >             Bug ID: 213873
> >            Summary: Hotplug ethernet cable to runtime suspended Realtek
> >                     NIC doesn't raise PCIe PME IRQ on Intel ADL
> >            Product: Drivers
> >            Version: 2.5
> >     Kernel Version: mainline
> >           Hardware: All
> >                 OS: Linux
> >               Tree: Mainline
> >             Status: NEW
> >           Severity: normal
> >           Priority: P1
> >          Component: PCI
> >           Assignee: drivers_pci@kernel-bugs.osdl.org
> >           Reporter: kai.heng.feng@canonical.com
> >         Regression: No
> >
> > Both PCIe bridge and Realtek NIC are runtime suspended. When ethernet cable is
> > plugged, PMEStatus and PMEPending are marked:
> > RootSta: PME ReqID 0200, PMEStatus+ PMEPending+
> >
> > But the IRQ isn't raised:
> > $ cat /proc/interrupts  | grep PME
> >  145:          0          0          0          0          0          0
> >  0          0          0          0          0          0   VMD-MSI  126  PCIe
> > PME, aerdrv, pcie-dpc
> >
> > So the hotplug event isn't detected.
> >
> > --
>
> From the lspci after cable hotplug (comment #3):
>
>   0000:00:1c.0 PCI bridge ...
>     RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible-
>     RootSta: PME ReqID 0200, PMEStatus+ PMEPending+
>
> So it looks like the root port is not enabled to generate a PME
> interrupt.  pcie_pme_interrupt_enable() looks like it *could* enable
> that.  From a quick look, my guess is that pme.c doesn't claim this
> root port because the platform says it doesn't support it:
>
>   acpi PNP0A08:00: _OSC: platform does not support [PCIeHotplug SHPCHotplug PME]
>   acpi PNP0A08:00: _OSC: OS now controls [AER PCIeCapability LTR]
>
> Does booting with "pcie_ports=native" make it work?  That's not a very
> good solution, of course, because then both the firmware and Linux
> think they own this functionality.

Yes, thanks for spotting this.

>
> Is there a BIOS update that would fix this?

This platform is still under enablement so we'll get a BIOS fix.

Kai-Heng

>
> Bjorn